Formal grammar, usage probabilities, and auxiliary contraction

This article uses formal and usage-based data and methods to argue for a hybrid model of English tensed auxiliary contraction combining lexical syntax with a dynamic exemplar lexicon. The hybrid model can explain why the contractions involve lexically specific phonetic fusions that have become morphologized and lexically stored, yet remain syntactically independent, and why the probability of contraction itself is a function of the adjacent cooccurrences of the subject and auxiliary in usage, yet is also subject to the constraints of the grammatical context. Novel evidence includes a corpus study and a formal analysis of a multiword expression of classic usage-based grammar.