The Columbia Encyclopedia, Sixth Edition. 2001-07.
verb
part of speech typically used to indicate an action. English verbs are inflected for person, number, tense and partially for mood; compound verbs formed with auxiliaries (e.g., be, can, have, do, will) provide a distinction of voice. Some English verblike forms have properties of two parts of speech (e.g., participles may be used as adjectives and gerunds as nouns). Verbs are also classified as transitive (requiring a direct object) or intransitive. In Latin verb inflection, voice and mood are indicated in every form. Most languages have a form class resembling that of English verbs. In many of them, unlike English, these words may form complete sentences, e.g., in Spanish, “I am singing” is expressed by the single word canto. Some languages (e.g., Turkish) can convey a great deal of information through modifications of form in the verb stem and ending, without the aid of auxiliary forms. A single word, for example, can indicate reciprocity, reflexivity, necessity, time, infinitive, number, person, and voice, as well as negative, causative, imperative, and intensive meanings.
