(6a) A howl rose.
(6b) *The audience rose a howl
(7a) Margaret slept.
(7b) *Margaret slept her bed.
We call these verbs intransitive and will label them "VI."
Unlike other types of verbs, intransitives can end sentences. Note, however, that intransitive verbs are not required to end the sentence. They can be followed by adverbs, prepositional phrases, and other optional elements:
(8) A howl rose from the audience.
(9) Margaret slept peacefully.
Such optional elements are called adjuncts of the verb phrase. Adjuncts can be added to any of the subtypes of verbs and don't serve to distinguish one subtype from another. We will return to adjuncts, and how to tell them apart from complements, after we have finished our survey of verb patterns.