Subject complements are defined as words, phrases, and clauses that follow a copular, or linking, verb and refer back to modify, describe, or complete the grammatical subject of the clause. Subject complements are grammatical constituents embedded in the predicate of a clause. Although nouns and adjectives most frequently function as the subject complement of clauses, five grammatical forms can perform the grammatical function of subject complement in English grammar:
- Noun phrases
- Adjective phrases
- Noun clauses
- Verb phrases
- Prepositional phrases
The following sections define and exemplify the five grammatical forms that can function as the subject complement in English grammar.
Noun Phrases as Subject Complements
The first grammatical form that performs the grammatical function of subject complement is the noun phrase. Noun phrases are defined as phrases that consist of a noun or pronoun plus any determinatives, modifiers, or complements. For example, the following italicized noun phrases function as subject complements:
- Your soup resembled mud. (noun)
- This is she. (pronoun)
- My daughter is a toddler. (noun phrase)
- Uncle Milo will become a doctor tomorrow evening. (noun phrase)
- The patron on the bench resembles the man on the wanted posters. (noun phrase)
- Grandma has remained a substitute teacher. (noun phrase)
- My husband is not a man of few words. (noun phrase)
- The former president was the most popular man in the world according to a magazine poll. (noun phrase)
Traditional grammars generally use the terms predicate nominative or predicate noun to refer to noun phrases functioning as subject complements.
Adjective Phrases as Subject Complements
The second grammatical form that performs the grammatical function of subject complement is the adjective phrase. Adjective phrases are defined as phrases that consist of an adjective plus any modifiers or complements. For example, the following italicized adjective phrases function as subject complements:
- The soup tasted awful. (adjective)
- My daughter got angry. (adjective)
- The mattress in the baby’s crib feels wet. (adjective)
- My mug of coffee is hot. (adjective)
- This blanket feels extraordinarily soft. (adjective phrase)
- The weather appears rather nice. (adjective phrase)
- The mood remained quite relaxed. (adjective phrase)
- My mother is fond of tulips. (adjective phrase)
Traditional grammars generally use the term predicate adjective to refer to adjective phrases functioning as subject complements.
Noun Clauses as Subject Complements
The third grammatical form that performs the grammatical function of subject complement is the noun clause. Noun clauses are defined as subordinate clauses that consist of a clause preceded by a subordinating conjunction. For example, the following italicized noun clauses function as subject complements:
- The problem is that you think grammar is difficult to learn.
- The best answer is whichever solution costs the least.
- My concern is what many students think about grammar.
- Your guest can be whomever you want to bring.
- The truth was that the moving company lost all your furniture.
- My question is whether you will sue the company for losses.
- Your mistake was that you refused to take lessons.
- The first place winner will be whoever swims the farthest in an hour.
Verb Phrases as Subject Complements
The fourth grammatical form that performs the grammatical function of subject complement is the verb phrase in the form of present participles and infinitives. Verb phrases are defined as phrases that consist of a verb plus any modifiers, complements, particles, or infinitive markers. For example, the following italicized verb phrases function as subject complements:
- His unique talent is singing opera in the shower. (present participle)
- Your weekend chores will be washing and folding the laundry. (present participle)
- My favorite hobby is learning about grammar. (present participle)
- Her favorite pastime is gardening. (present participle)
- The assignment is to read about subject complements. (infinitive)
- Your job duties are to shelve books and to dust shelves. (infinitive)
- Your only responsibility is to babysit your younger siblings. (infinitive)
- The instructions are to blanche the vegetables. (infinitive)
Traditional grammars generally use the term gerund to refer to verb phrases in the form of present participles that perform nominal functions including the subject complement.
Prepositional Phrases as Subject Complements
The fifth grammatical form that performs the grammatical function of subject complement is the prepositional phrase. Prepositional phrases are defined as phrases that consist of a preposition directly followed by a prepositional complement. For example, the following italicized prepositional phrases function as subject complements:
- The darkest time of night is after midnight.
- Grammar is out of this world.
- The grimiest place is under the freezer.
- My hiding place is under the bed.
- The best time to call is between six and nine.
- A good place to study is in the library.
- The worst part of my day is after lunch.
- My least favorite part of the workday is during the afternoon.
The five grammatical forms that can function as the subject complement in the English language are noun phrases, adjective phrases, noun clauses, verb phrases, and prepositional phrases.
Summary
Subject complements in English grammar are words, phrases, and clauses that follow a copular or linking verb and refer back to modify, describe, or complete the grammatical subject of the clause.
Subject complement is a grammatical function.
The grammatical forms that can function as the subject complement in English grammar are noun phrases including pronouns, adjective phrases, prepositional phrases, verb phrases, and noun clauses.
The terms predicate nominative and predicate noun are also used for noun phrases that function as subject complements. The term predicate adjective is sometimes used for adjective phrases that function as subject complements. Predicate nominative, predicate noun, and predicate adjective are also grammatical functions.
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.
