Phase Transitions in Language History

Languages change in fits and starts in a kind of punctuated equilibrium: a period of stasis followed by a structural shift manifested by several new phenomena.  We will illustrate from the history of English, discussing a change in word order and a change in category membership.  We will show how the singularity of the change in people's grammars explains the simultaneity of the changes in phenomena and how the nature of language acquisition by young children explains how the new grammars arise, following small changes in what children hear.