... structure along the following lines: ( 15) S PRN T VP We are V TP trying T VP to V PRN help you However, a structure such as ( 15) violates the two constituent structure ... constituent structure principles which we posited in (12) and (13) above. More particularly, the S analysis of clauses in ( 15) violates the Headedness Principle (12) in that the S we are trying to ... to help you 50 constituent-command), which provides us with a useful way of determining the relative position of two different constituents within the same tree (in particular, whether...