... (although, when, while) Reduced adverb clauses Adverb clauses that begin with after, before, since, when, and while are frequently reduced to phrases When reducing adverb clauses that begin with ... 3 Reduced adverb clauses An adverb clause can be changed to a reduced one if the subject of the main clause and the subject of the adverb clause are the same A reduced adverb clause ... discovered, penicillin has been used to treat bacterial infections 4 Verb tense of the adverb clauses In most adverb clauses, the verb has the same tense as the verb in the main clause Some exceptions...