Vivian Cook  SLA site  Paper on L1&L2 (2008)

Differences between L1 and L2 acquisition

Ellis 94 (based on Bley-Vroman 1988); updated in Cook (2008)


L1 acquisition

L2 (foreign language)

VC's objections

1. Overall 

children normally achieve perfect L1 mastery

adult L2 learners are unlikely to achieve perfect L2 mastery

All implicitly see 'success' in the sense of what a monolingual native speaker does, not an L2 user

2. General 

success guaranteed

complete success rare

3. Variation

little variation in degree of success or route

L2 learners vary in overall success and route

4. Goals

target language  competence

L2 learners may be content with less than target language competence or more concerned with fluency than accuracy

5. Fossilisation


common, plus backsliding (i.e. return to earlier stages of development

And L2 users too have L1 attrition

6. Intuitions

children develop clear intuitions about correctness

L2 learners are often unable to form clear grammaticality judgments

But bilingual children are better at this than mono-linguals

7. Instruction

not needed

helpful or necessary

All depends!

8. Negative 

correction not found and not necessary

correction generally helpful or necessary

Recasts are in fact based on L1 acquisition ideas

9. Affective 

not involved

play a major role determining proficiency

Again measured against monolinguals

Follow-up: Questioning Traditional Assumptions

Cook, V.J., Long, J., & McDonough, S. (1979), ‘First and second language learning’, in G.E. Perren (ed.) The Mother Tongue and Other Languages in Education, CILTR, 7-22 online here

1. The child’s language is a system in its own right rather than being a small fragment of the adult system
2. The learning of a first language has many sides and is not simply a matter of learning syntax and vocabulary
3. The use of the first language goes hand in hand with the child’s needs and interests
4. Wherever there is a relationship between cognition and language development, language depends on cognition
5. The child’s use and learning of language is partly determined by mental capacity
6. There are particular stages of development through which all children progress, even if the rate of progression varies
7. The child learns to adapt its language use to particular situations


Extract from V.Cook (2000) 'Linguistics and Second Language Acquisition: One Person with Two Languages', in Aronoff & Rees-Miller, Blackwell Handbook of Linguistics

What are the similarities between L2 learning and L1 acquisition?

A continuing theme has been whether people acquire a second language in the same way as a first. If the L2 stages outlined above are also followed by L1 children, both groups are probably using the same learning process. The L2 sequence for English grammatical morphemes was similar, though not identical, to that found in L1 acquisition by Brown (1972), the greatest differences being the irregular past tense (broke), articles (the), copula and auxiliaries (Dulay, Burt & Krashen, 1982). Other similar sequences of syntactic acquisition have been found in L1 and L2 learning. L2 learners, like L1 learners, start by believing that John is the subject of please in both John is easy to please and John is eager to please and only go on to discover it is the object in John is easy to please after some time (Cook 1973; d’Anglejan & Tucker 1975). L2 learners, like L1 children, at first put negative elements at the beginning of the sentence No the sun shining and then progress to negation within the sentence That’s no ready (Wode 1981).

A sub-theme underlying several of the questions discussed here is that L1 acquisition is completely successful, L2 learning is not. Take two representative quotations: ‘Very few L2 learners appear to be fully successful in the way that native speakers are’ (Towell & Hawkins 1994: p.14); ‘Unfortunately, language mastery is not often the outcome of SLA’ (Larsen-Freeman & Long 1991: 153). The evidence for this deficiency is held to be the lack of completeness of L2 grammars (Schachter 1988) or the fossilisation in L2 learning where the learner cannot progress beyond some particular stage (Selinker 1992), both familiar ‘facts’ in some sense. Part of the interest in SLA research is explaining why L2 learners are usually unsuccessful. However, this alleged failure depends upon how success is measured, as we shall see.

The answer to the question is far from settled. While there are many similarities between L1 and L2 learning, the variation in situation and other factors also produces many differences. One difficulty is filtering out differences that are accidental rather than inevitable. L1 children mostly acquire language in different settings with different exposure to language than L2 learners and they are at different stages of mental and social maturity (Cook 1969). It may be inherently impossible to compare equivalent L1 and L2 learners. A more precise version of this question asks whether adults still have access to Universal Grammar in the mind.


Cook, V.J. 1969. The analogy between first and second language learning. IRAL VII/3, 207-216, on-line version

Cook, V.J. 1973. The comparison of language development in native children and foreign adults. IRAL XI/1, 13-28, on-line version

d’Anglejan, A. & Tucker, G.R. 1975. The acquisition of complex English structures by adult learners. Language Learning, XV/2

Larsen-Freeman, D. & Long, M. 1991. An Introduction to Second Language Acquisition Research. Longman, London & New York

Schachter, J. 1988. Second Language Acquisition and its relationship to Universal Grammar. Applied Linguistics 9, 3, 219-235

Wode, H. 1981. Learning a Second Language. Tübingen: Narr