Reflexes of grammar in patterns of language change

ABSTRACT When one form replaces another over time in a changing language, the new form does not occur equally often in all linguistic contexts. Linguists have generally assumed that those contexts in which the new form is more common are those in which the form first appears and in which it advances most rapidly. However, evidence from several linguistic changes (most importantly the rise of the periphrastic auxiliary do in late Middle English) shows that the general assumption is false. Instead, at least for syntactic cases, change seems to proceed at the same rate in all contexts. Contexts change together because they are merely surface manifestations of a single underlying change in grammar. Differences in frequency of use of a new form across contexts reflect functional and stylistic factors, which are constant across time and independent of grammar.