When Does Do-insertion Take Place?

Chomsky (1995) and Lasnik (2000) propose that the dummy do is inserted at PF as a last resort when T-to-V hopping is impossible. This last resort approach is based on the assumption that T-to-V hopping and do-insertion are in complementary distribution. However, Embick & Noyer (2001) challenge the last resort approach by refuting the complementariness of T-to-V hopping and do-insertion. In this squib, however, I propose that their argument is not valid, and so we can still maintain the complementariness of the two operations, thereby supporting the last resort approach to do-insertion. In the course of providing arguments for the last resort approach, I propose that the sentential negator and the constituent negator are in complementary distribution, and modals, just like other types of auxiliary, undergo head movement to T.