8 Error Analysis and Interlanguage
of motivation. If the acquisition of the first language is a fulfilment of the predisposition to develop language behaviour, then the learning of the second language involves the replacement of the predisposition of the infant by some other force. What this consists of is in the context of this chapter irrelevant.
Let us say therefore that, given motivation, it is inevitable that a human being will learn a second language if he is exposed to the language data. Study of language aptitude does in some measure support such a view since motivation and intelligence appear to be the two principal factors which correlate significantly with achievement in a second language.
I propose therefore as a working hypothesis that some at least of the strategies adopted by the learner of a second language are substantially the same as those by which a first language is acquired. Such a proposal does not imply that the course or sequence of learning is the same in both cases.
We can now return to the consideration of errors made by learners. When a two year old child produces an utterance such as 'This mummy chair' -we do not normally call this deviant, ill-formed, faulty, incorrect, or whatever. We do not regard it as an error in any sense at all, but rather as a normal childlike communication which provides evidence of the state of his linguistic development at that moment. Our response to that behaviour has certain of the characteristics of what would be called if*-' 'correction' in a classroom situation. Adults have a very strong tendency to repeat and expand the child's utterance in an adult version; something like 'Yes, dear, that's Mummy's chair'.
No one expects a child learning his mother tongue to produce from the earliest stages only forms which in adult terms are correct or non-deviant. We interpret his 'incorrect' utterances as being evidence that he is in the process of acquiring language and indeed, for those who attempt to describe his knowledge of the language at any point in its development, it is the 'errors' which provide the important evidence. As Brown and Frazer (1964) point out the best evidence that a child possesses construction rules is the occurrence of systematic errors, since, when the child speaks correctly, it is quite possible that he is only repeating something that he has heard. Since we do not know what the total input has been we cannot rule out this possibility. It is by reducing the language to a simpler system than it is that the child reveals his tendency to induce rules.
In the case of the second language learner it might be supposed that we do have some knowledge of what the input has been, since this is largely within the control of the teacher. Nevertheless it would be wise to introduce a qualification here about the control of