Suggested answer for Exercise 4

In the sentence Bill caught a bird the main verb catch is a transitive verb. The subject is an agent, the object a patient. Since the vP is the extended projection of V, we can say that the DP in the specifier of the vP receives its thematic role indirectly from the main verb. The abstract light verb is a bound morpheme, which requires the main verb to adjoin to it. The DP in the specifier of the VP is assigned Case by the light verb. The other DP in the specifier of the vP also needs Case. Since that position is not a position to which Case is assigned, it has to move to the specifier of IP, where it receives Case from the finite I. The verb catch moves to tense v and then to I.