• The following sections of A Comprehensive Grammar of The English Language (Randolph Quirk, Sidney Greenbaum, Geoffrey Leech, Jan Svartik, Longman, London & New York, 1985) were consulted in preparing this entry:
Verb forms and the verb phrase
Finite verb phrases
Non-finite verb phrases
Simple and complex finite verb phrases
Simple and complex non-finite verb phrases
§3.56 153, 154
1. The explanation of the finite / non-finite distinction given in the main entry involves three of the five categories in the “grammatical hierarchy” — words, phrases, and clauses. Fundamentally however, the distinction is between types of word. (Finite verb phrases are finite because their first word is finite, and finite clauses are finite because their verb phrases are finite.) The distinction is based on a classification of the five sub-types of the “verb” word class, as either finite or non-finite: two of these sub-types, the -s form and the past tense form, are classified as finite; and two, the -ing form and the past participle are classified as non-finite. Matters are complicated, however by the fact that the fifth sub-type, the “base form” is sometimes finite and sometimes not. This is because this form, as well as occurring finitely, as the first-, second- and third-person plural of the simple present also occurs as the “bare infinitive” in verb phrases that begin with an auxiliary ( Harry does love Sara) and in to- infinitives (Harry hopes to get a divorce.)
2. Modal auxiliaries are clearly finite because they can occur as the first word in independent clauses and moreover because they cannot occur in any other position in the verb phrase. They are anomalous, however, because for modals the base form is the only form, and it is, moreover, always finite.
3. it is also important to emphasize — a point not explicitly made in the entry — that as well as occurring in the initial position of non-finite verb phrases, non-finite forms occur in all the non-initial positions of finite verb phrases.