With artificial intelligence (AI) now producing human-quality text in seconds via natural language generation, urgent questions arise about the nature and purpose of the teaching of writing in English. Humans have already been co-composing with digital tools for decades, in the form of spelling and grammar checkers built into word processing software. Yet AI has now advanced such that humans need to have less input in the writing process. This article contrasts these developments with findings from a small study of the teaching of writing in Victoria, Australia. The article proposes conceptual framing for these developments through dialogic encounters with Bill Green's model for compos(IT)ing and Rosi Braidotti's concept of the posthuman, making suggestions for updating thinking and offering practical strategies for future directions in the teaching of writing.