Functionalist Theories of SLA
Functionalist theories of L2 acquisition share a number of concerns with variability theories. For example, both are concerned not just with how linguistic knowledge is represented in the mind of the learner, but also with how this knowledge is used in discourse. Also, both types assume that syntax cannot be considered separately from semantics and pragmatics and, as such, are opposed to accounts of L2 acquisition based on a clear distinction between linguistic and pragmatic competence.
In a functionalist model, learning a language is seen as a process of mastering a number of fundamental functions of language—spatial and temporal reference, for instance,–and the linguistic means for conveying them. Thus, from this perspective, L2 knowledge is comprised of a network of form-function mappings. Initially the network is a relatively simple one but it gradually complexifies as the learner acquires new L2 forms, matches these to existing functions and uses them to realise new functions (Ellis, 2008).
The functional view of interlanguage development is closely associated with the work of Klein and Perdue. According to Klein (1991), language acquisition is functionally driven. He believes that “it is functions which drive the learner to break down parts of the input and to organise them into small subsystems, which are recognised whenever a new piece from the flood of input is added, until eventually the target system is reached (p. 220).
Functionalist researchers such as Perdue and Klein also emphasise the importance of discourse-contextual constraints on linguistic representation of interlanguage development. as Perdue (2000) put it “the learner has to learn how to reconcile the informational structure with the linguistic means available, and if this is not possible to acquire further means” (pp. 301-302). Learners variables are not just structured linguistically. They reflect the interaction of a limited set of organisational principles that operate at different levels—syntactic, semantic, and discoursal—with the specific interaction determining the nature of the learner variety from one time to the next.
Like Klein and Perdue, Givon (1979) also saw syntax as inextricably linked to discourse—it is ‘a dependent, functionally motivated entity’ in the sense that its formal properties reflect its communicative uses. Givon argued that learners progressively syntacticise their interlanguages as they move from a pre-grammatical to a grammatical mode. However, they retain access to the pre-grammatical mode which they employ when the conditions are appropriate. Givon also argued that other aspects of language, such as the historical evolution of languages and creolization, are also characterised by the same process of Syntactisation.