To communicate verbally, speakers must produce a grammatical sequence of words, that is, a sentence that conveys a meaning. The meaning activates syntactic, morphological, and lexical representations, which insure the production of a grammatical sentence. The process is surprisingly complex, because the speaker must select elements that are appropriate for the meaning and find a way to sequence these elements in a language-appropriate way.
To explain how speakers produce sentences, an architecture for sentence production has been proposed (e.g. Bock, 1995; Bock & Levelt, 1994; Garrett, 1988; Levelt, 1989). The architecture has three main components: the message, which represents the meaning of a sentence, the grammatical component, which is responsible for the generation of word sequences, and the phonological component, which retrieves the phonological content of words from the lexicon. Our discussion will focus on the mechanism of the grammatical component, that is, how a sentence is formulated in production (for discussion of the phonological component, see Terao, this volume, chapter 29).
Both observational and experimental techniques have been used to study production. Observational techniques examine the distribution of speech errors or syntactic structures in naturally occurring utterances (Garrett, 1988). While observational data reflect natural language use, the lack of experimental control has made it difficult to get precise answers about production processes. To get these answers, experimental methods have been developed (see Bock, 1996, for an exhaustive summary of existing techniques).