The notion of focus structure underlying the present work is essentially that of Lambrecht (1994), who distinguishes what he calls the predicate focus, argument focus and sentence focus types of focus structure. He illustrates this distinction by the A-utterances in (1), where the word in small capitals is the carrier of the primary sentence accent (see Lambrecht 1994:223):
(1) a. predicate focus structure
Q:What happened to your car?
A: My car/It broke down.
b. argument focus structure
Q: I heard your motorcycle broke down?
A: My car broke down.
c. sentence focus structure
Q:What happened?
A: My car broke down.