A predicate is defined as a word or phrase that expresses the action performed by the grammatical subject or the state of the grammatical subject. Within the predicate, individual verbs perform specific grammatical functions. The six grammatical functions performed by verbs within the predicate are:
- Predicate
- Progressive
- Perfect
- Passive
- Modal
- Operator
The following sections explain and exemplify the six grammatical functions performed by verbs within the predicate.
Predicates
The first grammatical function that a verb performs within the predicate is the predicate. A predicate is defined as a word or phrase that expresses the action performed by or condition of the subject. For example, the following italicized verbs function as predicates:
- My puppy ate the potato chip.
- His brother had been washing the dishes.
- The kitten has swallowed the yarn ball.
All clauses must contain a verb functioning as a predicate. The verb functioning as the predicate is also the head of the verb phrase.
Progressives
The second grammatical function that a verb performs within the predicate is the progressive. A progressive is defined as an auxiliary verb that expresses the progressive aspect. The progressive aspect expresses incomplete or ongoing actions or conditions at a specific time. The auxiliary verb that functions as the progressive is the verb be. For example, the following italicized verbs function as progressives:
- The student is alerting the teacher.
- Our neighbors were listening to loud music.
- She had been closing the windows when the storm hit.
Progressives must appear with predicates and can also appear with perfects, passives, and modals. Progressives cannot appear without a predicate.
Perfects
The third grammatical function that a verb performs within the predicate is the perfect. A perfect is defined as an auxiliary verb that expresses the perfect aspect. The perfect aspect expresses the consequences resulting from a previous action or condition. The auxiliary verb that functions as the perfect is the verb have. For example, the following italicized verbs function as perfects:
- Her parents have finally named her baby sister.
- The general had misled his troops.
- My brother has sold his old car.
Perfects must appear with predicates and can also appear with progressives, passives, and modals. Perfects cannot appear without a predicate.
Passives
The fourth grammatical function that a verb performs within the predicate is the passive. A passive is defined as an auxiliary verb that expresses the passive voice. The passive voice is a grammatical voice that moves the object of an active sentence into the subject position. The auxiliary verbs that function as the passive are the verbs be and get. For example, the following italicized verbs function as passives:
- The cookies have been eaten by the children.
- The crops got harvested last week.
- The house is being painted by professionals.
Passives must appear with predicates and can also appear with progressives, perfects, and modals. Passives cannot appear without a predicate.
Modals
The fifth grammatical function that a verb performs within the predicate is the modal. A modal is defined as an auxiliary verb that expresses modality. Modality expresses possibility, necessity, and contingency. The nine auxiliary modal verbs that function as modals are can, could, may, might, must, shall, should, will, and would. The five quasi-modal verbs that function as modals are ought (to), had better (had best), used to, dare, and need.
- You need not ask if you may borrow the car tonight.
- By the time I could start, you will have already finished.
- You must wash your hands before eating.
Modals must appear with predicates and can also appear with progressives, perfects, and passives. Modals cannot appear without a predicate and can appear only in predicate phrases.
Operators
The sixth grammatical function that a verb performs within the predicate is the operator. An operator is defined as an auxiliary verb that facilitates the expression of a negation, interrogatives, and emphasis. The auxiliary verb that functions as the operator is the verb do. For example, the following italicized verbs function as operators:
- Do you like cucumbers?
- He does not care for acorn squash.
- The baby sure did enjoy the pumpkin puree!
Operators must appear with predicates but cannot appear with other auxiliary verbs. Operators cannot appear without a predicate and can appear only in predicate phrases.
The six functions of verbs within the verb phrase functioning as the predicate are predicate, progressive, perfect, passive, modal, and operator.
References
Brinton, Laurel J. & Donna M. Brinton. 2010. The linguistic structure of Modern English, 2nd edn. Amsterdam: John Benjamins Publishing Company.
Hopper, Paul J. 1999. A short course in grammar. New York: W. W. Norton & Company.
Huddleston, Rodney. 1984. Introduction to the grammar of English. Cambridge: Cambridge University Press.
