- He came quickly.
- He came on time.
- He came when he was called.
In the first sentence the word quickly is an adverb modifying the verb came and answers the question when. It tells when he came. In the second sentence, the phrase on time is an adverb phrase modifying the verb came, and answers the question when. It tells when he came. In the third sentence, the clause when he was called, also answers the question when, and tells when he came. Therefore, it is a clause used as an adverb. It is different from the phrase on time, for the phrase on time does not contain a subject and a predicate.
348. The difference between the phrase and the clause is that the phrase does not contain either a subject or a predicate, while the clause always contains both a subject and a predicate. So in the clause, when he was called, he is the subject and was called is the predicate, and when is the subordinate conjunction, which connects this adverb clause to the verb came, which it modifies. The clause he came, and the clause when he was called, are not of equal rank and importance, because the clause, when he was called, simply modifies the verb contained in the clause he came, by describing the time of the action expressed in the verb came. So the clause, when he was called, is a subordinate or dependent clause, and the conjunctions which connect this class of clauses to the main clause are called subordinate conjunctions.
349. A subordinate conjunction is one that connects a dependent clause to the principal clause.
CLASSES OF SUBORDINATE CONJUNCTIONS
350. Most subordinate conjunctions are used to make adverb clauses. These clauses will answer some one of the questions answered by adverbs. They will tell how, when, where or why the action expressed in the verb in the principal clause occurred. There are six classes of these subordinate conjunctions which are used to introduce adverb clauses. They introduce:
351. Adverb clause of time. These clauses will answer the question when and are introduced by such subordinate conjunctions as, before, since, as, while, until, when, after and as soon as. Notice in the following sentences the difference made in the meaning of the sentences by the use of the different conjunctions:
- We waited until you came.
- We waited after you came.
- We waited as you came.
- We waited before you came.
- We waited since you came.
- We left while you were gone.
- We left when you were gone.
- We left as soon as you were gone.
352. Adverb clause of place. These answer the question where, and are introduced by the conjunctions, where, whence, whither.
- I will go where you go.
- The wind blows whither it listeth.
- He went whence he came.