Answer :
Answer:
After I went to bed last night
Explanation:
In the sentence, there are two clauses: an independent clause: the telephone rang twice (because it expresses a complete thought) and a dependent clause: After I went to bed last night (Because it does not express a complete thought on its own).
Dependent clauses can work as adjectives, nouns, or adverbs in a sentence. An adverb clause modifies verbs, adjectives or other adverbs and they are often introduced by a coordinating conjunction such as after, before, until and because. When they are placed at the beginning of a sentence (such as in the sentence given), they begin with a coordinating conjunction and end with a comma: After I went to bed last night, the telephone rang twice.
So, in the sentence, "After I went to bed last night" is an adverb clause because it has all those characteristics, and it modifies or adds further information to the verb "rang twice", more specifically, it answers the question When?: When did the telephone ring twice? Answer: After I went to bed last night.