Prepositions are notionally defined by traditional grammars as a word that “links to other words, phrases, and clauses” and that “expresses spatial or temporal relations.” A prepositional phrase consists of a preposition plus another word, phrase, or clause functioning as the prepositional complement.
In grammar, a subject complement is a word, phrase, or clause that follows a copular, or linking, verb and describes the subject of a clause. Although nouns including pronouns and noun phrases most frequently perform the function, prepositional phrases sometimes, although rarely, function as subject complements in English. Examples of prepositional phrases as subject complements include the following:
- The most magical time of night is after midnight.
- Studying English grammar is out of this world.
- My least favorite part of the workday is during the afternoon.
- A good place to study is in the library.
- The grimiest place in the kitchen is under the refrigerator.
- The worst part of my day is after lunch.
Prepositional Phrase as Subject Complement
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.