In traditional grammar and guide books, a linking verb is a verb that describes the subject by connecting it to a predicate adjective or predicate noun (collectively known as subject complements). Unlike the majority of verbs, they do not describe any direct action taken or controlled by the subject.
Linking verbs include copulas such as the English verb be and its various forms, as well as verbs of perception such as look, sound, or taste and some other verbs that describe the subject, such as seem, become, or remain. In addition to predicate adjectives and predicate nouns, English allows for predicate prepositional phrases as well: John is behind the cocktail cabinet.
The following sentences include linking verbs.