In Early Modern English, verbal negation was commonly expressed by the addition of not directly after a lexical verb, a construction which subsequently underwent a pronounced decline in frequency as part of broader changes in verbal syntax. Even after the rise of the auxiliary do, however, constructions with the same surface form as the earlier pattern have continued to be used as a stylistically marked alternative. Data from the Hansard Corpus are presented here to show an increase in the frequency of these constructions since the mid twentieth century. The syntactic environments in which contemporary postverbal negation occurs are compared to the patterns existing in Early Modern English, and evaluated in the light of trends within constituent negation. The interpretation proposed is that a lexical split has occurred to produce two separate lexemes of the form not, with different syntactic properties. Postverbal negation would thus occur in Present-day English when speakers choose to make use of the new lexeme.