In 1953 Ulrich Weinreich talked about interference as 'deviation from the norms of either language which occur in the speech of bilinguals as a result of their familiarity with more than one language' (Weinreich, 1953: 1). This fits with everybody's common-sense belief that your first language (L1) has an effect on your second language (L2). The foreign accents we hear confirm this every day; an English speaker can tell whether someone is French or  Japanese after a few words of English. In the fifty years since Weinreich's book, there has been extensive research into how the learning and use of a second language is affected by the first language, whether conceived as Contrastive Analysis, transfer, cross-linguistic influence, resetting of parameters or in many other ways.

Yet few people seemed to notice that Weinreich's definition concerned deviation in either language. As well as the first language influencing the second, the second language influences the first. Perhaps this effect is less detectable in our everyday experience: only complex instrumental analysis of a Spanish speaker's accent in Spanish may reveal whether they also know English. It only becomes blatant when the first language starts to disappear, for instance when a speaker brings more and more L2 words into their first language.

This volume is perhaps the first book devoted only to the effects of the second language on the first, sometimes called 'reverse' or 'backward' transfer. It arose out of an invitational workshop held in Wivenhoe House in 2001, at which all the papers included were delivered, apart from two (Porte, Chapter 6; Cook et al, Chapter 10). By using a variety of perspectives, methodologies and languages, the research reported here shows that the first language of people who know other languages differs from their monolingual peers in diverse ways, with consequences for second language acquisition research, linguistics and language teaching. The range of contributions shows the extent to which this question impinges not only on all the areas of language from vocabulary to pragmatics but also on a variety of contemporary approaches currently being developed by second language acquisition (SLA) researchers.

The book is intended for researchers in second language acquisition research and bilingualism, students and teachers around the world. The breadth of the contributions in terms of countries, languages, aspects of language and theories means that it relates to most SLA courses at some point whether at undergraduate or postgraduate level.

This introduction provides some background to the different contributions in this volume. It tries not to steal their thunder by anticipating their arguments and conclusions but provides a more personal overview, with which of course not all of the writers will be in complete accord. It relies in part on a summary overview of issues provided to the writers by Batia Laufer after the conference. It does not attempt to deal with the vast areas of language transfer from L1 to L2 or with the field of language attrition, covered in say classic texts like Odlin (1989) or Weltens et al (1986).

For me, and for many of the contributors, the question of L2 effects on the L1 arose out of the notion of multi-competence. Initially the term was used almost as a convenience; while the 'interlanguage' had become the standard term for the speaker's knowledge of a second language, no word existed that encompassed their knowledge of both the second language and their first: on the one hand the L1, on the other the interlanguage, but nothing that included both. Hence 'multi-competence' was introduced to mean 'knowledge of two or more languages in one mind' (Cook, 1991). For convenience we will mostly talk about 'second language' and bilingualism here but this does not preclude multiple languages and multilingualism.

Since the first language and the other language or languages are in the same mind, they must form a language super-system at some level rather than completely isolated systems. Multi-competence then raised questions about the relationship between the different languages in use: how do people code-switch fluently from one language to another? how do they 'gate out' one language while using the other (Lambert, 1990)? how do they manage more than one pragmatic and phonological system? It also raised questions about cognition: does an L2 user have a single set of ideas in the mind, more than one set of ideas, a merged set from different languages, or a new set of ideas unlike the sum of its parts? And multi-competence also led inevitably to questions about acquisition: what roles do the first language and the other language or languages play in the creation of knowledge of the second or later languages?

Multi-competence led me in particular to a re-valuing of the concept of the native speaker (Cook, 1999). While the concept of interlanguage had seemed to establish the second language as an independent language system, in effect second language acquisition research still treated the L2 system in an L2 user as an approximation to an L1 system in someone else (i.e. a monolingual L1 user). SLA research methods compared knowledge of L2 syntax against the knowledge of native speakers (Cook, 1997). Whether L2 learners had access to Universal Grammar was seen as a matter of whether they learnt the same grammars as monolingual native speakers – ‘slightly over half of the non-native speakers typically exhibit the correct UG-based judgements on any given UG effect’ (Bley-Vroman, Felix & Ioup, 1988: 24). Whether age affected L2 learning was seen as how close people came to monolingual native speakers - 'whether the very best learners actually have native-like competence' (Long, 1990: 281). Whether they had an accent was a matter of how native-like they were – 'the ultimate goal – perhaps unattainable for some – is, nonetheless, to "sound like a native speaker" in all aspects of the language’ (González-Nueno, 1997: 261). The independence of interlanguage was largely illusory since the norm against which the L2 user was compared was almost universally the native speaker, whether overtly or covertly.

The arguments against the native speaker standard have been mounting over the past ten years. Let us first define the native speaker as 'a monolingual person who still speaks the language they learnt in childhood' (Cook, 1999). This combines the priority of the language in the development of the individual and the continuity of use by the individual with the usual simplifying assumption in linguistics that native speakers are monolingual. It does not preclude the possibility of a person being a native speaker of more than one language, if they acquired them simultaneously while children. By this definition, however, it is impossible for an L2 user to become a native speaker – one reason why so many L2 users think of themselves as 'failures' and so many SLA researchers treat them in the same way: 'learner's language is deficient by definition' (Kasper & Kellerman, 1997: 5).

The main arguments against the use of native speakers as the norm against which L2 users should be measured are:

• the rights of L2 users

One group of human beings should not judge other people as failures for not belonging to their group, whether in terms of race, class, sex or language. People should be measured by their success at being L2 users, not by their failure to speak like native speakers. The object of acquiring a second language should be to become an L2 user, not to pass for a native speaker. SLA research has to do justice to its constituency - people who know two languages - not subordinate them to people who only know one language. The L2 user is a person in their own right (Cook, 1997; Grosjean, 1989), not an imitation of someone else.

• the numbers of L2 users

Precise figures about the numbers of monolingual native speakers in the world are hard to arrive at. It is slightly easier in reverse to find some numbers for people who are learning or using second languages. Taking English as an example, the British Council (1999) claims that a billion people are studying English in the world, including all children over 12 in Japan. English is used everywhere for certain purposes, such as academic journals and the internet; many people communicate with each other through English who never meet a native speaker, for example businesspeople doing international deals. Some countries where English is hardly spoken at all natively, such as Singapore, deliberately use it as a 'first language'; others employ it as an official language, for example Nigeria, Cameroon, India and Pakistan. Turning away from English, most people in say Capetown, Islamabad or Brussels switch from one language to one or more other languages in their daily lives. Monolingual native speakers are far from typical of human beings and are increasingly hard to find in the world (as we shall see in some of the contributions here), even in the highlands of Papua New Guinea. While it may be hard to prove that L2 users actually make up the majority of human beings, they at least form a very substantial group.

The usual resort in SLA and bilingualism research is to see the L2 standard in terms of the balanced bilingual or 'ambilingual'. Toribio (2001: 215) for instance defines a balanced bilingual as 'a speaker who has native-like ability in two languages' and sees the standard against which an L2 user is measured as being 'an idealised bilingual's native speaker competence'. While the construct of the native speaker competence may be appropriate in first language acquisition as all human beings attain it, the concept of idealised bilingual competence can be extremely misleading since so few L2 users attain it: how many people have native-like skills in both languages in a reasonable range of their contexts of language use? They are the exception rather than the norm among L2 users, defined by their ability to function like native speakers in two languages not by their whole language ability to use two languages. The use of a native speaker measure that is virtually impossible to achieve, even when disguised as the double monolingual native speaker of the balanced bilingual, will blind us in the future as it has done in the past to the overwhelming majority of L2 users who are far from native-like across two languages. First language acquisition research is about what most people achieve, not the abilities of monolingual Shakespeares. Second language acquisition research should equally be about what typical L2 users achieve, not about bilingual Nabokovs. Hence I now try to avoid the word 'bilingual' in discussing people who know two languages, not only because of the plethora of confusing definitions, but also because they usually invoke a Platonic ideal of the perfect bilingual rather than the reality of the average person who uses a second language for the needs of their everyday life.

• the distinctive characteristics of L2 users

If L2 users are different kinds of people, the interest of SLA research lies in discovering their characteristics, not their deficiencies compared to native speakers. In Cook (2002a: 4-8) the characteristics of L2 users are stated as four propositions:

1. the L2 user has other uses for language than the monolingual.

2. the L2 user's knowledge of the second language is typically not identical to that of a native speaker.

3. the L2 user's knowledge of their first language is in some respects not the same as that of a monolingual.

4. L2 users have different minds from monolinguals.

This book is thus primarily an expansion and justification of proposition 3 that L2 users differ in their knowledge of their first languages from monolingual native speakers. Inevitably it simultaneously provides further information about the distinctive nature of the L2 user's uses for language, their knowledge of their second language and their minds.

Multi-competence led to seeing the L2 user as a person in their own right, not as an approximation to a monolingual native speaker. This is why I prefer the term 'L2 user' to 'L2 learner' in recognition of the person's ability to use the language rather than remaining a learner in perpetuity, always recognising that the same person may be both 'learner' and 'user' in different aspects of their language identities.

The belief in the native speaker standard is one reason why the effects of the L2 on the L1 were so little studied: if the L1 of the L2 user were different from that of monolingual native speakers, SLA research that used the native speaker as the target would be based on shifting sand. As argued in Cook (2002a), a comparison of the L2 user with the native speaker may be legitimate provided any difference that is discovered is not treated as a matter of deficiency; persistent use of this comparison prevents any unique features of the L2 user's language being observed since only those that occur in natives will be searched for. This led for example for many years to a view that code-switching in adults or children was to be deplored rather than commended; Genesee (2002) for instance discusses how young children's code-switching was interpreted as a sign of confusion rather than as skilful L2 use.

While this argument has been couched in terms of multi-competence, this is not the only approach for dealing with the effects of the L2 on the L1. In this volume we find general models such as the dynamic model of multilingualism of Jessner (Chapter 12), the Common Underlying Conceptual Base of Kesckes and Papp (Chapter 13), Karmiloff-Smith's Representational Redescription Model and Bialystok's Analysis/Control Model (Murphy & Pine, Chapter 8), and variants on the Chomskyan Minimalist Program used by Balcom (Chapter 9) and Satterfield (Chapter 11). Most of these share the assumption that at some level the L2 user's mind is a whole that balances elements of the first and second language within it. Furthermore, as Satterfield argues, this is essentially the normal state all human beings can reach and so has to form the basis for any account of human language. If monolingualism is taken as the normal condition of humanity, L2 users can be treated as footnotes to the linguistics of monolingualism. With most people in the world learners or users of second languages, however, monolinguals can be considered the exception, not only statistically but also in terms of human potential.

What could the logical relationships actually be between the two or more languages in the mind? One possibility is that the languages are in watertight compartments, seen in the separation model in Figure 1.1, akin to the idea of coordinate bilingualism associated with Weinreich (1953); the L2 user either speaks one language or the other, with no connection between the different languages in the mind. The early SLA research controversies about the natural order of acquisition asserted a separation model in which the L2 interlanguage developed without drawing on the L1 to any great extent (e.g., Dulay & Burt, 1980). The separation model forms the basis for much language teaching methodology, which teaches without reference to the first language and discourages its use in the classroom, hoping that the students will build up a new language system with no links to the first. This model sees no point to discussing the effects of the L2 on the L1, as they do not exist. Separation does not, by the way, imply anything one way or the other about universals of language whether language design (Hockett, 1960) or innate properties of the mind (Chomsky, 2000). Both separate languages might be similar because they are governed by the same constraints and potentials as any other language acquired by a human being.

[Look on this space and imagine two separate circles]

Figure 1.1. Separation model

The opposite possibility is that the languages form a single system, shown in the integration model in Figure 1.2. In the area of vocabulary some people have claimed that, rather than two separate mental lexicons, the L2 user has a single lexicon where words from one language are stored alongside the other (Caramazza & Brones, 1980). In terms of phonology some have found that L2 users have a single merged system for producing speech, neither L1 nor L2 (Williams, 1977). Integration does not say that L2 users are unable to control what they do; they can still choose which language to use in a given context, just as a monolingual can choose which style or register to adopt in a particular situation. In this model, the discussion is not about the influence of L2 on L1, but about the balance between elements of a single language system. Indeed there is little point to counting 'languages' in a single mind – L1, L2, L3, Ln – as they form a single system.

[Look on this space and imagine a single circle]

Figure 1.2. Integration Model

Clearly neither of these two models can be absolutely true: total separation is impossible since both languages are in the same mind; total integration is impossible since L2 users can keep the languages apart. These possibilities represent the end-points on the integration continuum (Cook, 2002a; Francis, 1999). In between these two extreme, and probably untenable, positions of total separation and total integration, there are many different degrees and types of interconnection, two of which are shown in Figure 1.3 below.

The linked languages model A in Figure 1.3 captures the idea of influence between two essentially separate language systems in the same mind, i.e. it is a variant of the separation model in which the two separate language components interact with each other. This is perhaps the typical model assumed in much SLA research; development and use of the L2 is affected by the already existing L1, as surveyed say in Odlin (1989). Studies of language 'transfer' or 'influence' have assumed an interconnection model by seeing how the development of interlanguage – the L2 element in multi-competence – takes advantage of the first language – the L1 element in multi-competence. The linked languages model does, however, allow the links to go in both directions: the Revised Hierarchical Model of the lexicon (Kroll & Tokowicz, 2001) for instance assigns unequal strengths to the links between L1 and L2 according to direction and stage of acquisition.

[For A imagine two circles linked by a double-head arrow; for B two overlapping circles]

The variant called the partial integration model (Figure 1.3B) captures the idea of partial overlapping of the two language systems in the same mind; i.e. it is a limited version of the integration model. Inevitably this is bi-directional in a particular area since, like the integration model, it does not distinguish between languages in the areas of overlap but sees how the single conjoined system differs from monolingual versions of either language. There may be shared or overlapping vocabulary, syntax, or other aspects of language knowledge. Van Hell & Djikstra (2002), for example, show that 'the multilingual's processing system is profoundly non-selective with respect to language' (p. 1) and that the lexicon of the language that is not overtly in use is nevertheless still active.

One question is whether the differences between the two conceptualisations of interconnection - linked languages and partial integration - are alternative wordings of the same idea, as implied in Cook (2002a), or represent different types of relationship. Is there a difference between saying that the languages in the mind are merged towards the integration end of the continuum or that the links between them are stronger? This may partly be settled by the research in this volume, or indeed by neurolinguistic approaches such as Fabbro (2002).

Figure 1.4 then displays the integration continuum as a whole and is equivalent to the figure in Cook (2002a: 11). The continuum does not necessarily imply a direction of movement. It may be that some people start with separation and move towards integration or vice versa, or the languages might stay permanently separate. Paradis and Genesee (1996) for example see bilingual children as having 'autonomous' languages from early on rather than 'interdependent' languages.

The integration continuum does not necessarily apply to the whole language system (Cook, 2002a); a person's lexicon might be integrated, their phonology separate. Nor does it necessarily affect all individuals in the same way; some may be more integrated, some not, a factor of individual variation subsuming Weinreich's types of bilingualism. The point on the continuum may also vary from moment to moment in the individual according to their perception of language mode (Grosjean, 2001), their level of tiredness and other personal factors; or indeed, as Porte suggests in Chapter Six, because of fondness for language play by L2 users. The continuum might also be related to different stages of L2 development; children may move from an integrated single lexicon to a less integrated double lexicon (Taeschner, 1983). One important aspect of this question may indeed be to establish which areas of the L1 are not affected by the L2, for example the lexical diversity or productivity studied by Dewaele and Pavlenko (Chapter 7). The concept of the integration continuum is discussed in more detail in the context of bilingual concepts in Cook (2002a, 2002b).

Again there are several alternatives to the integration continuum way of conceptualising L2 influence on L1. Pavlenko (Chapter 3) describes five forms of 'transfer'; Kecskes and Papp (Chapter 13) describe six variations on the L2 on L1 effect. Many of these variations concern whether the second language is the majority or minority language in the community or in the individual (Li Wei, 1994), whether it is taught in a classroom or learnt outside, whether it acts as a lingua franca, and so on.

The integrative continuum has certain differences from the concept of language modes. Grosjean (2001) puts any language use by an L2 user on a continuum of monolingual and bilingual modes according to the proportions of language A and language B, or indeed language C, that are involved; 'language mode is the state of activations of the bilingual's languages and language processing mechanisms at a given point in time (Grosjean, 2001: 3). An L2 user decides the proportions of the two languages to employ at any given moment in the light of multiple factors on a continuum between effectively activating only one language or activating both simultaneously. The language mode continuum is not then about which language to use but about how much of each. It is like a mixer tap that merges hot and cold water, but neither tap can be completely turned off. The way in which the language mode concept is phrased still implies the existence of two (or more) languages, two (or more) separate mental entities who strike a balance for each language use rather than integration of the two languages. Grosjean (2001) for instance questions the methodologies that have produced signs of integration in semantics and word perception by pointing out that they paid insufficient attention to language mode. The partial integration model denies, however, that are two languages as such and favours a single mental system within which a balance can be struck between elements for a particular aspect of language in a particular situation. This is one of the reasons why this introduction has tried to avoid the word 'transfer' (the other motives being its confusing multiple definitions and its emotive connotations): it is questionable whether links between elements in the same mind can be considered transfer without in effect 'counting' languages (Cook, 2000).

The Integration Continuum fits with the Dynamic Model of Multilingualism (Jessner, Chapter Twelve) in trying to see the language system of the L2 user as a whole rather than as an interaction between separate language components. It is similar to the Common Underlying Conceptual Base (Kecskes and Papp, Chapter 13) in seeing the effects of the second language as affecting the whole mind. It is also compatible with the integrated neurolinguistic theory of bilingualism (Paradis, 2001) in unifying both L1 and L2 within the same architecture of the mind. The Integration Continuum does not spell out the separate L1 and L2 components of pragmatics, semantics, morphosyntax and phonology that are part of the Paradis model but implies that the relationship of integration versus separation varies from component to component without naming the components. It differs, however, in extending the continuum to concepts, where Paradis (2001) has a single unvarying conceptual system. If speakers of different languages do in fact have different concepts, such as relative versus absolute orientation (Levinson, 1996) and form versus substance categorisation of objects (Imai & Gentner, 1997), models of L2 users clearly must accommodate variation in cognition and some relationship between the specifically L1 and specifically L2 concepts (Cook, 2000, 2002b); for example Athanasopolos (2001) showed that Greeks who knew English had a different perception of the colour 'blue' than Greeks who did not.

The integration continuum has been presented here positively as the separation or integration of two languages in the same mind. However these L2 on L1 effects could be evaluated in at least three ways: positive effects on the L1, negative effects on the L1, and effects that are essentially neutral.

It seems obvious that in some sense knowing another language benefits your use of your first language; language teaching classically invoked the concept of 'brain-training' to justify the teaching of Latin for example. Hungarian children who know English use measurably more complex sentences in their first language than those who do not (Kesckes & Papp, 2000). Extensive research into bilingual development shows overall that L2 user children have more precocious metalinguistic skills than their monolingual peers (Bialystok, 2001). English children who are taught Italian for an hour a week read English better than those who are not (Yelland et al, 1993). So far as the general use of the first language is concerned, it is an advantage to know a second language, as the many celebrated bilingual writers attest, ranging from Chinua Achebe to John Milton, Samuel Samuel Beckett to Rabindranath Tagore. In the present volume the enhancing effects of the second language can be found in the contribution in this volume by Murphy and Pine (Chapter 8) on the development of bilingual children in England.

The usual context for discussing possible harmful effects of the L2 on the L1 is language loss or attrition. We will set aside here the effects on the L1 of other factors than the L2, say aphasia caused by brain damage (Paradis, 2000). As a person gains the ability to use a second language, so they may to some extent lose the ability to use their first language. In circumstances where one language becomes less and less used, people do lose their command of it, whether as a group or as individuals. Perhaps this is familiar to everybody whose school-learnt language has effectively vanished from their lives. Research into this has mostly been carried out the context of the loss of the first language by people who are spending their lives in a situation where it is not used for their major everyday social and professional purposes, whether as immigrants or expatriates. Examples of such research in this volume are Porte's account of expat teachers of English (Chapter 6) and Laufer's account of Russian L1 speakers in Israel (Chapter 2).

Positive and negative evaluations of differences are to some extent problematic in that they rely on a value judgment about what is good and bad. Enhanced metalinguistic ability is only valuable if it is useful in some definable way; losing some aspect of the first language is only a disadvantage if it prevents the L2 user carrying out some activity successfully.

Many of the effects of the L2 on the L1 simply amount to differences. The L2 user mind is bound to have differences in the first language element because of its more complex linguistic organisation, whether through linking or integration. In phonology the extensive literature on Voiced Onset Times in L2 users, surveyed in Watson (1990), reveal time and again the differences in the first language of L2 users for plosive consonants such as /p/ and /b/ or /k/ and /g/ across pairs of languages such as Spanish/English (Zampini and Green, 2001), French/English (Flege, 1987), and Hebrew/English (Obler, 1982), which are essentially undetectable in normal language use. In this volume the contribution by Cook et al (Chapter 10) shows differences in L1 sentence-processing by Japanese L2 users that are hard to regard as either positive or negative; the changes that Jarvis (Chapter 5) finds in the L1 Finnish of a Finn again seem neither good nor bad. L2 users in a sense simply have a different command of the L1, which cannot be either commended or disapproved of. It is a complete system of its own, as the work by Cenoz with Spanish learners of English suggests (Chapter 4).

We have already seen the breadth of approaches used in looking at the effects of L2 on L1. The basic methodological paradigm is the comparison of monolingual native speakers with speakers of the same language who know a second language. At least two factors are probably more crucial in this type of research than in others.

The initial need is to find two similar groups who differ in whether or not they know a second language. The papers in this volume tackle Russians who do or do not know Hebrew (Laufer, Chapter 2); bilingual and monolingual children in England (Murphy & Pine, Chapter 8); Japanese, Greek and Spanish-speaking adults who do or do not know English (Cook et al, Chapter 10); Canadian francophones who do or do not know English (Balcom, Chapter 9); Cubans using English in the United States who had been there a short while and those who had been there a long time (Satterfield, Chapter 11); and many other combinations.

Finding two comparable groups with and without an L2 is easier said than done. The consequence of the wide-spread use of second languages is that monolingual native speakers are hard to come by. Where in the world can one find people who have not at least studied a second language in school? (Actually, given current government proposals to minimise languages in the National Curriculum, this may soon be the case in England).

If L2 effects on L1 only happen at advanced stages of the L2, it would be safe to count as monolinguals people who had only a smattering of a second language, say as a school subject. Restricting monolingual subjects to those who had never studied a language at school might reduce them to people who had not completed education or who had had a non-standard education or to those who were too old to have had a compulsory language. Furthermore, as Bialystok (2001) argues, eliminating those with low levels of the L2 in advance would prejudge the issue by assuming that there are no effects at early stages, which is by means certain. Indeed, if Yelland et al (1993)'s results are correct, one hour of an L2 in the primary school per week can affect the L1, at least in the area of reading.

Or it might be possible to include people who had learnt a second language provided it was a different second language. English people who had learnt German might be put in the monolingual group so far as the learning of French was concerned. The danger is that L2 learning in general produces some effects on the L2 user, such as enhanced metalinguistic ability: a grammaticality judgment test might be contaminated if the person had learnt any other language, not just the particular language tested in the experiment. This becomes even more dangerous if the effects of the L2 on people's linguistic judgements cannot be predicted from a conjunction of the first and second languages but is something different from both, as we find in Chapter 10 (Cook et al.)

The solution that has often to be resorted to is to abandon the attempt to contrast 'pure' monolinguals with L2 users. One possibility is to try for minimal versus maximal bilinguals, say people who have had the least possible exposure to another language versus those who have studied it at university level, as is done by Cook et al (Chapter 10). Cenoz (Chapter 4) comes to a similar solution by comparing Spanish university students who were 'non-fluent' in English in that they had only studied it at school with those who were 'fluent' by virtue of receiving all their university tuition through English.

Underlying many of these factors is the difficulty in equating the two groups for various social factors. Those who have learnt another language may, compared to the monolingual control, either be in a higher socio-economic group as with elite bilingualism or in a lower socio-economic group as with asylum seekers or migrant workers, or in the case of university students doing different subjects may differ in personality profiles and career ambitions.

In addition the problem is sometimes that the L2 user who is part of a minority in a culture may be socialising with a group of fellow L1 speakers. Over time these isolated L1 communities may evolve their own languages. Gal (1989) described Hungarian speakers living in Austria who invented new Hungarian words as they did not know the actual forms used in Hungary. Many of the EFL students I once taught in West London were members of the expatriate Polish community; one of them, however, was an actress who was in England temporarily to act in the Polish theatre. She told me that members of the audience had complained about her terrible accent in Polish, while in fact she had the educated accent then spoken in Warsaw. Languages change. The L1 spoken in the larger L1 community may change, as in this case, so that L2 users who are cut off from it are inevitably out of date in their usage – say at the extreme of Welsh speakers in Patagonia or French speakers in Pondicherry. The L1 used by minority groups may change and adapt to its circumstances, as in Pennsylvania Deitsch in the United States. Cantonese speakers in Newcastle for instance say tiojau ('table wine') rather than jau ('wine) as used in Hong Kong and bafong ('bathroom') rather than saisanfong (Li Wei, 1994: 66).

In these complex social situations it is hard to decide whether there is really an effect of L2 on L1 or there has simply been an evolutionary change in the L1 as spoken by particular groups. The changes in the Finnish woman living in United States described by Jarvis (Chapter 5) are particularly interesting because she does not take part in the Finnish expatriate community. One of the causes of linguistic change overall is indeed the contacts with other cultures; how else could English have absorbed vocabulary such as bungalow, kangaroo or ciabatta except by eventual effects on the L1s of its speakers?

The next factor is choosing a testing instrument that can be used with both groups. Among the different possibilities used in this volume are: elicitation of narratives by showing subjects films (Pavlenko, Chapter 3), a standardised discourse completion test (Cenoz, Chapter 4), assignment of the subject of the sentence (Cook et al, Chapter 10), naturalistic observation (Porte, Chapter 6), grammaticality judgments (Balcom, Chapter 9; Laufer, Chapter 2), reaction time experiments (Murphy & Pine, Chapter 8), and statistical measures of lexical diversity and productivity (Dewaele & Pavlenko, Chapter 7). In their chapters both Jarvis (Chapter 5) and Kecskes and Papp (Chapter 13) discuss the issue of research techniques further.

The problem that we found with the research reported in Chapter 10 was how the nature of the task varied across languages. A sentence that provides a particular clue to the subject of the sentence, say number agreement, is useless when translated and tested in a language with no agreement; a sentence that in English carries no clue about gender has to specify gender when translated into many other languages, this providing unwelcome additional cues. A task like grammaticality judgments depends on many cultural attitudes towards correctness and status, which may well be altered in people who know another language - again one of the goals of language teaching is often given as greater tolerance of linguistic variety. Toribio (2001) has pioneered the use of grammaticality judgments with code-switching, a fully appropriate use that recognises the distinctive language of the L2 user.

In particular Grosjean (1998, 2001) has highlighted the effects of the subject's awareness of language mode on experiments. Does the task try to put the L2 users on their mettle as L1 users? Or do they see it as a test of their second language? This links to the observer effect, as emphasised by Li Wei (2000): do they feel the experimenter is a fellow L2 user or a judgmental monolingual native speaker? How they present themselves is affected by their perception of the testing situation as one in which the first or second language is involved.

The issue of whether the second language affects the second has then provided a rich new question for second language acquisition research to investigate, the first fruits of which are seen in this volume. It has profound implications not only for our conceptualisation of the mind with two languages but for our view of all human minds.

Athanasopolos, P. (2001) L2 acquisition and bilingual conceptual structure. MA thesis, University of Essex.

Bialystok, E. (2001) Bilingualism in Development. Cambridge: Cambridge University Press.

Bley-Vroman, R.W., Felix, S. & Ioup, G.L. (1988) The accessibility of Universal Grammar in adult language learning. Second Language Research 4 (1), 1-32.

British Council (1999) Frequently asked questions. Online document: http://www.britishcouncil.org/english/engfaqs.htm#hmlearn1).

Caramazza, A. & Brones, I. (1980) Semantic classification by bilinguals. Canad. J. Psychol. 34, 1, 77-81.

Chomsky, N. (2000) The Architecture of Language. New Delhi: Oxford University Press.

Cook, V.J. (1991) The poverty-of-the-stimulus argument and multi-competence. Second Language Research 7, 2, 103-117.

Cook, V.J. (1997) Monolingual bias in second language acquisition research. Revista Canaria de Estudios Ingleses 34, 35-50.

Cook, V.J. (1999) Going beyond the native speaker in language teaching. TESOL Quarterly 33, 2, 185-209.

Cook, V.J. (2000) Is transfer the right word? Paper presented at the 7^th International Pragmatics Conference, July, 2000. Budapest. On-line at privatewww.essex.ac.uk/~vcook/OBS8.htm.

Cook, V.J. (2002a) Background to the L2 user. In V.J. Cook (ed.) Portraits of the L2 User (pp. 1-28). Clevedon: Multilingual Matters.

Cook, V.J. (2002b) Bilingual cognition. Paper presented at the EUROSLA Annual Meeting, Basel, September.

Dulay, H.C. & Burt, M.K. (1980) On acquisition orders. In S. Felix (ed.) Second Language Development: Trends and Issues. Tübingen: Narr.

Fabbro, F. (2002) The neurolinguistics of L2 users. In V.J. Cook (ed.) Portraits of the L2 User (pp. 167-195). Clevedon: Multilingual Matters.

Flege, J.E. (1987) Effects of equivalence classification on the production of foreign language speech sounds. In A. James & J. Leather (eds.) Sound patterns in second language acquisition (pp.9-39). Dordrecht: Foris.

Francis, W. (1999) Cognitive integration of language and memory in bilinguals: Semantic representation. Psychological Bulletin 125, (2), 193-222.

Gal, S. (1989) Language and political economy. Annual Review of Anthropology 18, 345-67.

Genesee, F. (2002) Portrait of the bilingual child. In V.J. Cook (ed.) Portraits of the L2 User (pp. 167-196). Clevedon: Multilingual Matters.

González-Nueno, M. (1997) VOT in the perception of foreign accent. IRAL XXXV/4, xxx-261.

Grosjean, F. (1998) Studying bilinguals: Methodological and conceptual issues. Bilingualism: Language and Cognition 1 (2), 131-149.

Grosjean, F. (2001) The bilingual's language modes. In J. Nicol (ed.) One Mind, Two Languages (pp. 1-22). Oxford: Blackwell.

Grosjean, F. (1989) Neurolinguists, beware! The bilingual is not two monolinguals in one person. Brain and Language 36, 3-15.

Hockett, C.F. (1960) The origin of speech. Scientific American, 203, 88-9.

Imai, M., and Gentner, D., 1997 A crosslinguistic study of early word meaning: universal ontology and linguistic influence. Cognition 62. 169-200

Kasper, G. & Kellerman, E. (eds) (1997) Communication strategies: psycholinguistic and sociolinguistic perspectives. Harlow: Longman.

Kecskes, I. & Papp, T. (2000) Foreign Language and Mother Tongue. Hillsdale, NJ: Lawrence Erlbaum.

Kroll, J.F. & Tokowicz, N. (2001) The development of conceptual representation for words in a second language. In J. Nicol (ed.) One Mind, Two Languages (pp. 49-71). Oxford: Blackwell.

Lambert, W.E. (1990) Persistent issues in bilingualism. In B. Harley, P. Allen, J. Cummins and M. Swain (eds.) (1990) The Development of Second Language Proficiency (pp. 201-220). Cambridge: Cambridge University Press.

Levinson, S.C (1996) Relativity in spatial conception and description. In J.J. Gumperz and S.C. Levinson (eds.) Rethinking Linguistic Relativity (pp. 177-202), Cambridge: Cambridge University Press.

Li Wei (1994) Three Generations, Two Languages, One Family. Clevedon: Multilingual Matters

Li Wei (2000) Methodological questions in the study of bilingualism. In L1 Wei (ed.) The Bilingualism Reader (pp. 475-486). London Routledge.

Long, M. (1990) Maturational constraints on language development. Studies in Second Language Acquisition 12, 251-86.

Obler, L. (1982) The parsimonious bilingual. In L. Obler and L. Menn (eds.) Exceptional Language and Linguistics (pp XXX-XXX). New York: Academic Press.

Odlin, T. (1989) Language Transfer: Cross-Linguistic Influence in Language Learning. Cambridge: Cambridge University Press.

Paradis, J. & Genesee, F. (1996) Syntactic acquisition in bilingual children. Studies in Second Language Acquisition 18, 1-25.

Paradis M. (2000) Bilingual and polyglot aphasia. In R.S. Berndt (ed.) Handbook of Neuropsychology (Second Edition). Oxford: Elsevier Science.

Paradis, M. (2001) An integrated neurolinguistic theory of bilingualism 1976-2000. LACUS Forum, XXVII

Taeschner, T. (1983) The Sun is Feminine. Berlin: Springer.

Toribio, A.J. (2001) On the emergence of bilingual code-switching competence. Bilingualism: Language and Cognition 4, 3, 203-232.

Van Hell, J.G. & Dijkstra, T. (in press) Foreign language knowledge can influence native language performance in exclusively native contexts. Psychonomic Bulletin and Review.

Watson, I. (1991) Phonological processing in two languages. In E. Bialystok (ed.) Language Processes in Bilingual Children (pp. 25-48). Cambridge: Cambridge University Press.

Weinreich, U. (1953) Languages in Contact. The Hague: Mouton.

Weltens, B., De Bot, K. & van Els, T. (1986) Language Attrition in Progress. Dordrecht: Foris.

Williams, L. (1977) The perception of consonant voicing by Spanish English bilinguals. Perception and Psychophysics 21, 4, 289-297.

Yelland, G.W., Pollard, J. & Mercuri, A. (1993) The metalinguistic benefits of limited contact with a second language. Applied Psycholinguistics 14, 423-444.

Zampini, M.L. and Green, K.P. (2001) The voicing contrast in English and Spanish: the relationship between perception and production. In J. Nicol (ed.) One Mind, Two Languages (pp. 23-48). Oxford: Blackwell.