A verb that is followed by an object is called a transitive verb. Transitive verbs can be classified by the number of objects they require. Verbs that require only two arguments, a subject and a single direct object, are monotransitive. Verbs that require two objects, a direct object and an indirect object, are ditransitive, or less commonly bitransitive. An example of a ditransitive verb in English is the verb to give, which may feature a subject, an indirect object, and a direct object: John gave Mary the book. Verbs that take three objects are tritransitive. In English a tritransitive verb features an indirect object, a direct object, and a prepositional phrase – as in I'll trade you this bicycle for your binoculars – or else a clause that behaves like an argument – as in I bet you a pound that he has forgotten. Not all descriptive grammars recognize tritransitive verbs.
A clause with a prepositional phrase that expresses a meaning similar to that usually expressed by an object may be called pseudo-transitive. For example, the Indonesian sentences Dia masuk sekolah ("He attended school") and Dia masuk ke sekolah ("He went into the school") have the same verb (masuk "enter"), but the first sentence has a direct object while the second has a prepositional phrase in its place. A clause with a direct object plus a prepositional phrase may be called pseudo-ditransitive, as in the Lakhota sentence Haŋpíkčeka kiŋ lená wé-čage ("I made those moccasins for him"). Such constructions are sometimes called complex transitive. The category of complex transitives includes not only prepositional phrases but also dependent clauses, appositives, and other structures. There is some controversy regarding complex transitives and tritransitives; linguists disagree on the nature of the structures.
In contrast to transitive verbs, some verbs take zero objects. Verbs that do not require an object are called intransitive verbs. An example in English is the verb to swim.
Verbs that can be used in an intransitive or transitive way are called ambitransitive verbs. In English, an example is the verb to eat; the sentences You eat (with an intransitive form) and You eat apples (a transitive form that has apples as the object) are both grammatical.
The concept of valency is related to transitivity. The valency of a verb considers all the arguments the verb takes, including both the subject and all of the objects. In contrast to valency, the transitivity of a verb only considers the objects. Subcategorization is roughly synonymous with valency, though they come from different theoretical traditions.