1-Liliane Haegeman Introduction to Government and Binding Theory (1991:241) on c-command
3-VISH: the assumption there is that the whole VP, not the V, assigns a theta-role to the subject. So, in expletive structures, the subject originates in spec-VP, and in non-expletive structures it moves out of VP to spec-IP:
- There are two people here.
- Two people are here.