This volume brings together a number of articles on the form and function of extra-clausal constituents, a group of linguistic elements which have puzzled linguists by defying analysis in terms of ordinary sentence grammar. Given their high frequency and communicative importance, these elements can, however, no longer be dismissed as a marginal linguistic phenomenon. In recent years this awareness has resulted not only in more systematic treatments of extra-clausal constituents, but has also highlighted the need to account for them in grammatical theory. Based on (mainly English) corpus data, the volume investigates the discourse-pragmatic, semantic, syntactic and phonological features of a range of extra-clausal constituents, including discourse markers, free adjuncts, left dislocands, insubordinate clauses and various kinds of adverbials. The individual chapters adopt a number of different perspectives, investigating the diachronic development of extra-clausal constituents, their multi-functionality and their use in bilingual settings, also addressing the question of how they can be incorporated into existing models of grammar.