When a verb is called “intransitive,” it means that no stated object follows it. It would be an error in English to say “I’m waiting you” because the verb “wait” is an intransitive verb. The term “intransitive” contrasts with the term “transitive.” When used in a sentence, a transitive verb is always followed by some noun, pronoun, or noun phrase that is its object. Many verbs can be used both transitively (with an object) or intransitively (without an object). The verb “walk,” for example, is often used intransitively, as in “She’s walking,” but it can also be used transitively, as in “She’s walking the dog.” Click here for further discussion of transitive versus intransitive verbs.
Intransitive verbs are not found in as many verb patterns as transitive verbs, but some intransitive verbs can be followed by infinitives, as in “Would you care to sit down?” Intransitive verbs are sometimes followed by nothing at all, as in the sentences “He’s sleeping,” “I hesitated,” “She waited,” and “They apologized.” But very often they are followed by other things, such as adverbs, adverbials (i.e., phrases or clauses that function like adverbs), or by prepositional phrases as in the following examples.
He’s sleeping soundly. [soundly = adverb]
I hesitated when I saw her looking so upset. [when I saw her looking so upset = adverbial clause]
She waited for you = [for you = prepositional phrase]
They apologized for making a disturbance. [for making a disturbance = prepositional phrase]