An adverb clause is a dependent clause that modifies a verb in another clause. Sometimes an adverb clause will modify another clause in its entirety, rather than just the verb in that clause.
II. How can I recognize an adverb clause?
Just like any other adverbial element, an adverb clause will give adverbial information, by responding to one of the adverbial questions:
How much? (To what degree?)
The subordinators for adverb clauses (i.e., the words that make them dependent clauses) are subordinating conjunctions. The most common subordinating conjunctions are
in order that
If you examine each of these conjunctions, you will see that a clause introduced by any of them will provide adverbial information. For example, after (When?), as if (How?), until (When?), for (Why?), because (Why?), so that (Why?), if (How? Under what circumstances?), although (Why?--negation of expected cause).
In each of the following sentences, the adverb clause is underlined and in italics, and the subordinating conjunction is in maroon.
~He lived with his motheruntil she died.
~The elements joined by a conjunction are said to be coordinateif those elements are grammatically equal.
~I won't buy the car unless I get some sort of warranty with it.
~Nero fiddled while Rome burned.
~Becky can't go swimming today because she has a sore throat.
~Turn off the lightwhen you leave so that my electric bill won't be so high.(There are two adverb clauses in this sentence.)
~She looked right through meas if I were not there.
~We'll never work well together as long as you take that attitude toward the job.
III. How do I punctuate an introductory adverb clause?
When the adverb clause precedes the clause that it modifies, then it is an introductory adverb clause. Treat it as about a 95% rule that an introductory adverb clause should be followed by a comma.
~Until she died, he lived with his mother.
~If the elements joined by a conjunction are grammatically equal, the elements are said to be coordinate.
~While Rome burned, Nero fiddled.
~Because she has a sore throat, Becky can't go swimming today.
~When you leave, turn off the light so that my electric bill won't be so high.
~So that my electric bill won't be so high,turn off the light when you leave.
~As long as you take that attitude toward the job, we'll never work well together.
~Unless I get some sort of warranty, I won't buy the car.