- 21 -
Subject Complements

The professor is very hard
They were in trouble here this week

Predicate Adjectives. The most common subject complement of be and other linking verbs is an adjective or adjective phrase. Just as noun phrases (or pronouns) which occur as subject complements are called predicate nominatives, so we call adjectives in this position predicate adjectives. As usual, the adjective's main function is to modify a noun--in this case, the subject:

(1) The professor is very hard.

As a general rule, linking verbs which can also be used in transitive or intransitive predicates can only take predicate adjectives as their subject complements. The verbs get, grow, prove, and turn, for example, can all be used as linking verbs roughly equivalent to become, but they are only used with adjectival complements. This saves English users from a certain amount of confusion:

(2) Dan gets angry.
(3) George grew weary.
(4) Hannah proved unreliable.
(5) Jane turned prudish.

Another group of linking verbs limited to adjectival complements are the so called sensory verbs, like feel, look, smell, sound, taste. They can be tricky to distinguish from the same verbs used as transitive or intransitive verbs:

(6) Dan felt angry.
(7) George looks weary.
(8) Hannah smells sweet.
(9) Jane sounds prudish.
(10) Hannah tastes sweet.

A Very Hard Tree. Drawing a PS tree for a sentence which has an adjective phrase as a subject complement is just like drawing one for a sentence with a noun phrase. The adjective phrase is still a complement, so we show it as forming the verb phrase along with the verb. If the adjective phrase has a degree word, we want the diagram to show that the degree word and adjective go together to make up the adjective phrase. We'll use Adj and AdjP here for adjectives and adjective phrases; one can also use just A and AP:

Predicate Adverbs. There remain some sentences with be as the main verb which have neither noun phrases or adjectives as complements:

(11) The end is here.
(12) The end is soon.
In these sentences, the subject complements "here" and "soon" are adverbs and they are being used as predicate adverbials. Here is an adverb of place, also called a locative. Soon is an adverb of time. Those are the only kind of adverbs which can appear as subject complements--just as they are the only adverbs to serve as postmodifiers in noun phrases.

Exercise 1: Kinds of Predicates

Remembering that some verbs can be used more than one way, say whether the underlined verbs in the sentences below are: (A) linking verbs with subject complements, (B) transitive verbs with direct objects, or (C) intransitive verbs with no complements at all.
1.01 All the robbers fled.
1.02 The car smells bad.
1.03 Edward tasted the wine.
1.04 Grace looks hot.
1.05 My aunt paused for a moment.
1.06 Andy left last week.
1.07 The schedule seems workable.
1.08 Superman stopped the bullet.
1.09 Tina was naughty.
1.10 The villains robbed the grave

Telling Adjectives from Adverbs. Some people have trouble distinguishing adverbs from adjectives. The "very" test doesn't help, because many adverb phrases can also start with "very." Most of the time, of course, adverbs are modifying verbs, and adjectives are modifying nouns, but both can serve as subject complements. One structural test that usually works is to see what happens when one moves the subject complement into the subject NP. Except for old-fashioned expressions like "attorney general," single adjectives will always precede the main noun. Adverbs can (and usually do) follow the main noun:

(13) The dog is rabid. = The rabid dog
(14) The dog is here. = The dog here

Another test is to substitute an intransitive verb for be. Place and time adverbs should still sound grammatical because they can also be used as adjunct modifiers of the verb in a VP, giving us sentences like these:

(15) The dog sings here.
(16) The dog sings soon.

Adverbials. Just as there are nominal structures which can serve the sentence functions served by noun phrases, there are adverbials which can serve the functions usually served by adverbs. Prepositional phrases are especially frequent as adverbials, and such place or time adverbials are common subject complements; like those adverbs, they come after the main noun if one moves them into the subject NP.

(17) The train was on time.
(18) The party was after midnight.
(19) Lucy was in the parlor.
(20) They were in trouble.

Less frequently, one finds noun phrases serving as adverbials of place or time:

(21) The meeting was this week.
If one wants to be precise, these count as predicate adverbials and not as predicate nominals, even though they are NPs. When they are modifying verbs,, such adverbials can be moved about within the sentence, just like the equivalent adverbs:
(10) (a) They were in trouble here last week.
(b) Last week they were in trouble here.

Exercise 2: Varieties of Subject Complements

Say whether the underlined subject complements below are (A) predicate adjectives, (B) predicate adverbials, or (C) predicate nominals. To make it easier for you, adverbial NPs are not included in this exercise, just adverbs and adverbial prepositional phrases.
2.01 The meeting was yesterday.
2.02 My sister is a teacher.
2.03 Our appointment is at noon.
2.04 Our pet crocodile is outside.
2.05 Something smells fishy.
2.06 The novel sounds good.
2.07 Greta was in a jam.
2.08 Marianne became very angry.
2.09 George felt dizzy.
2.10 This is the worst party in years.

In drawing PS trees for these structures, the most complicated is the preposition phrase (PP), where we need to make it clear the complement NP is part of the PP. Adverbs just get labelled as such, and adverbial NPs can be treated like other noun phrases.

Just for the Record: More on Identifying Adverbs. Like gradable adjectives, adverbs can also form the They can also form comparatives (with more or an -er ending) and superlatives (with most or an -est ending). There is a distinctive derivational affix by which we make adverbs from adjectives, and which we use to recognize adverbs, and that is the -ly ending. Unfortunately, we are so used to forming adverbs from adjectives by adding -ly, that we sometimes simply assume that all words with that ending are adverbs. Unfortunately, English has a group of very old adjectives that were formed the same way, including kindly, lovely, and friendly. Watch out for them.

How Much of This Will be on the Test?
This section has dealt with two more kinds of subject complements: predicate adjectives and predicate adverbials (which are always place or time adverbs). In any given clause, you should be able to recognize the kind of main verb (transitive, intransitive, linking), and the kinds of complements (if any) which accompany it.