Abstract

Most linguists assume, either implicitly or explicitly, that all native speakers of the same language have more or less the same mental grammar. It is, of course, well established that there are vast individual differences in lexical knowledge and knowledge of archaic, formal and literary grammatical constructions (e.g. Little did I know that…); all speakers, however, are thought to share the same ‘core’ grammar.

In this talk, I summarise a number of recent studies showing that this is not the case. The studies involved several different aspects of linguistic knowledge, including inflectional morphology, passives, quantifiers, and a variety of more complex constructions with subordinate clauses. For some of these constructions, language learners attend to different cues in the input and end up with different grammars; for others, some speakers acquire only fairly specific, ‘local’ generalizations which apply to particular subclasses of items while others extract more abstract rules.

These results are problematic for theories which assume that language acquisition is largely predetermined by an innate Universal Grammar shared by all members of our species. They also raise interesting questions about what we mean by “knowing a language”: if different members of a speech community have different grammars, in what sense can they be said to speak the same language? Finally, they add to the growing body of research on the relationship between linguistic proficiency and educational success, and suggest that difficulties with language may be a major cause of school failure among children from socially disadvantaged backgrounds.