81) a. run, feel happy, study English syntax, . . .
b. can run, will feel happy, must study English syntax, . .
We have seen that the expressions in (81a) all form VPs, but how about those in (81b) and (81c)? These are also VPs, which happen to contain more than one V. In fact, the parts after the auxiliary verbs in (81b) and (81c) are themselves regular VPs. In the full grammar we will consider to and can and so on as auxiliary verbs, with a feature specification [AUX +] to distinguish them from regular verbs. Then all auxiliary verbs are simply introduced by a second VP rule:17
(82) VP--V[AUX +] VP
One more important VP structure involves the VP modified by an adverb or a PP:
(83) a. John [[read the book] loudly].
b. The teacher [[met his students] in the class].