217 Subordinate clauses
A sentence can contain a main clause and one or more subordinate clauses. A subordinate clause is a group of words containing a subject and verb and forming part of a sentence:
We knew that the bridge WUB unaafe.
He gave it to me because he trusted me.
He ran foster than we did.
This is Ike picture that I bought in Rome. On the examples above and in 218 the subordinate clauses are in bold type.)
For other examples see under conditional sentences, relative pronouns and clauses of purpose, comparison, time, result and concession. It ic not necessary for the student to make a detailed study of clauses or even to §c able to recognize the different kinds of clause, but it is necessary for him to learn to know which is the main verb of a sentence because of the important rule given below.
218 The sequence of tenses
When (he main verb of a sentence is in a past tense, verbs in subordinate clauses are normally in a past tense also. See the starred sentences below.
Tense of verb in mam clause
Tense of verb in subordinate clause
Present
Past
Present
Past
Present
Past
Pres. ptrf.
Pastperf.
Present
Put
Ht dunks that it will nun. He thought that it would rain. *
Ht stts th»t hf ham mmflf m mimtmlrf
Future simple
Co< optional
Pres. perf.
Past perf.
Present
Past
Present
Past
Pres. continuous
Past continuous
He saw that he had made a miatake. * I work so Hard that I am always tired. I worked so hard that I waa alwaya find. * He has done all that it neceaaary. He kod done all that waa neceaaary. * He says that he it going to eat it. He said that he waa going to eat it. •
Note that infinitive and gerunds are not affected by the above rule: Ht wants to go to Lyons. He wanted to go to Lyons. He likes riding. He liked riding.
The rule about sequence of tenses applies also to indirect speech when the introductory verb is t a past tense. (See chapter 31.)
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