Chomsky’s (1965), attempt to explain how children acquire successfully their
mother tongue, despite the fact that their input is often inadequate and minimal, has
led him to suggest that human beings are endowed with a common underlying system,
a Language Acquisition Device (LAD) as he called it, which contains characteristics
which are shared by all languages. Chomsky later replaced the term LAD with that of
‘Universal grammar’ which he defined as consisting of ‘… the set of properties,
conditions, or whatever, that constitute the ‘initial’ state of the language learner,
hence the basis on which knowledge of language develops’ (Chomsky 1980: 69).
Thus, as Wood (1988: 95) comments, for Chomsky a valid theory of language must
include a distinction between what he termed the ‘deep’ and ‘surface’ structure of
utterances. The surface structure is the physical manifestation of an utterance (i.e. a
series of sound waves or a sequence of letters in print). Since a similar meaning can
be conveyed by quite different sound and print patterns, there cannot be a simple
relationship between surface structure and meaning. The same set of sounds can have
more than one meaning (ambiguity) and the same meaning can be expressed by
different surface structures (paraphrase). Consequently, there must be a ‘deeper’
structure underlying speech which is common to all languages.
Although Chomsky did not make any reference to the pedagogical
implications of his theory, both first and second language teaching were strongly
influenced by it. Ellis (1999: 30) stresses that Chomsky’s theory displaced the concept
of ‘analogy’ which Skinner had evoked to account for the language user’s ability to
generate novel sentences with that of ‘creative construction’ as a result of the
learner’s innate ability to systematize language and thus it emphasized the learner’s
contribution to the whole process of acquisition. According to Brown (1987: 20), the
contribution of Chomsky and others working within the nativist tradition is that they
helped us to see that a child’s language, at any given point, is a legitimate system in
its own right which is continually revised, reshaped or, sometimes, abandoned
through a process of hypothesis forming and testing. Moreover, as Wood (1988: 91)
emphasises, the view of an innate ability for language processing has led to the
argument that ‘… children are not taught to speak at all, nor, in any simple sense, do
they learn language, by imitation, say. Rather, children acquire their mother tongue.’
As Lighbown and Spada (1999: 16) comment, for the LAD to work, the child needs
access only to samples of a natural language which serve as a trigger to activate the
device. Once the device is activated, the child is able to discover the structure of the
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