An adverbial clause is a dependent clause that functions as an adverb; that is, the entire clause modifies a verb, an adjective, or another adverb. As with all clauses, it contains a subject and predicate, although the subject as well as the (predicate) verb may sometimes be omitted and implied (see below).
An adverbial clause is commonly, but not always, fronted by a subordinate conjunction—sometimes called a trigger word. (In the examples below the adverbial clause is italicized and the subordinate conjunction is bolded.)
- Mary, the aspiring actress, became upset as soon as she saw the casting list.
- (subject: she; predicate: saw the casting list; the clause modifies the verb became)
- Peter Paul, the drama teacher, met with Mary after she came to the next class.
- (explicit subject: she; predicate: came to the next class.; predicate (verb): came; the clause modifies the verb met;)
- He talked carefully in order to appear fair.
- He talked carefully in order .. [that 'he'] appear fair.
- (implied subject, he, is omitted; predicate (verb): appear; the clause modifies the adverb carefully)
- The little boy preferred fierce dinosaurs, as T rex.
- The little boy preferred fierce dinosaurs, as [was] T rex.
- (subject of the clause: T rex; predicate of the clause: [was], implied; the clause modifies the adjective fierce.)
According to Sidney Greenbaum and Randolph Quirk, adverbial clauses function mainly as adjuncts or disjuncts, which parts also perform in a sentence as adverbial phrases or as adverbial prepositional phrases (Greenbaum and Quirk,1990). Unlike clauses, phrases do not contain a subject and predicate; they are contrasted here:
- We left the convention the day before.
- (adverbial phrase; contains no subject or predicate)
- We left before the speeches.
- (adverbial prepositional phrase; contains no subject or predicate—and no verb (action) is implied)
- We left after the speeches ended.
- (adverbial clause; contains subject and predicate)
- We left after the speeches.
- or, (".. after the speeches [ended]")
- (adverbial clause; contains subject and predicate, but the verb 'ended' is omitted and implied)
Adverbial clauses are divided into several groups according to the actions or senses of their conjunctions:
|Type of clause||Common conjunctions||Function||Example|
|time||Conjunctions answering the question "when?", such as: when, before, after, since, while, as, as long as, till, until, etc.;||These clauses:
Say when something happens by referring to a period or point of time, or to another event.
|Her goldfish died when she was young.
He came after night had fallen.
We barely had gotten there when mighty Casey struck out.
|condition||if, unless, lest||Talk about a possible or counterfactual situation and its consequences.||If they lose weight during an illness, they soon regain it afterwards.|
|purpose||in order to, so that, in order that||Indicate the purpose of an action.||They had to take some of his land so that they could extend the chuchyard.|
|reason||because, since, as, given||Indicate the reason for something.||I couldn't feel anger against him because I liked him too much.|
|concession||although, though, while||Make two statements, one of which contrasts with the other or makes it seem surprising.||I used to read a lot although I don't get much time for books now.|
|place||Answering the question "where?": where, wherever, anywhere, everywhere, etc.||Talk about the location or position of something.||He said he was happy where he was.|
|comparison||as...as, than, as||State comparison of a skill, size or amount, etc.||Johan can speak English as fluently as his teacher.
She is a better cook than I.
|manner||Answering the question, "how"?: as, like, the way||Talk about someone's behavior or the way something is done.||I was never allowed to do things as I wanted to do them.|
|results||so...that, such...that||Indicate the result(s) of an act or event.||My suitcase had become so damaged that the lid would not stay closed.|
- Greenbaum, Sidney & Quirk, Randolph. A Student's Grammar of the English Language. Hong Kong: Longman Group (FE) Ltd, 1990.
- Sinclair, John (editor-in-chief). Collins Cobuild English Grammar. London and Glasgow: William Collins Sons & Co ltd, 1990.