A cognitive approach to grammar is concerned with modelling the language system (the mental 'grammar') in ways which are consistent with the generalisation commitment and the cognitive commitment associated with the larger cognitive linguistics enterprise. Cognitive approaches also adhere to the two guiding principles of cognitive approaches to grammar. These are the symbolic thesis and the usagebased thesis. In addition, cognitive approaches take as their starting point the conclusions of work in cognitive semantics. This follows as meaning is central to cognitive approaches to grammar; although the study of cognitive semantics and cognitive approaches to grammar are occasionally separate in practice, this by no means implies that their domains of enquiry are anything but tightly linked. Indeed, most work in cognitive linguistics finds it necessary to investigate both semantics and grammar in tandem.

Researchers who adopt a cognitive approach to grammar have typically adopted one of two foci.

Scholars such as Ronald Langacker have emphasised the study of the cognitive principles that give rise to linguistic organization. In his theory of cognitive grammar, Langacker has attempted to delineate the principles that structure a grammar and to relate these to aspects of general cognition.

The second avenue of investigation, pursued by researchers including William Croft, Charles Fillmore and Paul Kay, Adele Goldberg, George Lakoff, Laura Michaelis and others, and more recently Benjamin Bergen and Nancy Chang, aims to provide a more descriptively and formally detailed account of the linguistic units that comprise a particular language. These researchers attempt to provide a broad-ranging inventory of the units of language, from morphemes to words, idiomatic expressions and phrasal patterns, and seek accounts of their structure, compositional possibilities and relations. Researchers who have pursued this line of investigation are developing a set of theories that are collectively known as construction grammars. This general approach takes its name from the view in cognitive linguistics that the basic unit of language is a form-meaning pairing known as a construction (1).