This book proposes that subjective expression shapes grammatical and lexical patterning in American English conversation. Analyses of structural and functional properties of English conversational utterances indicate that the most frequent combinations of subject, tense, and verb type are those that are used by speakers to personalize their contributions, not to present unmediated descriptions of the world. These findings are informed by current research and practices in linguistics which argue that the emergence, or conventionalization, of linguistic structure is related to the frequency with which speakers use expressions in discourse. The use of conversational data in grammatical analysis illustrates the local and contingent nature of grammar in use and also raises theoretical questions concerning the coherence of linguistic categories, the viability of maintaining a distinction between semantic and pragmatic meaning in analytical practice, and the structural and social interplay of speaker point of view and participant interaction in discourse.