Traditional grammars notionally define the preposition 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 disjunct adverbial is a word or phrase that provides additional information to frame an entire clause. Disjunct adverbials denote the attitude of the speaker toward or judgment of the proposition such as truthfulness of manner of speaking. In addition to adverb phrases, prepositional phrases sometimes function as disjunct adverbials in English. Examples of prepositional phrases as disjunct adverbials include the following:
- In my opinion, learning about grammar is fun.
- For the love of goodness, the children need to stop whining.
- With all due respect, you need to calm down.
- According to the new study, eating excess sugar causes heart disease.
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.