The document summarizes six classes of verb phrases:
1. Transitive verbs require a direct object.
2. Intransitive verbs do not take an object.
3. Ditransitive verbs require two objects - a direct object and an indirect object.
4. Intensive verbs include verbs like be, seem, appear, and become.
5. Complex-transitive verbs have an object complement in addition to a direct object.
6. Prepositional verbs require a prepositional phrase to be complete.