原因状语从句

原因状语从句

(1)原因状语从句通常由because, since, as引导。例如:

①He didn’t come to school because he was ill.

②As it is raining, we shall not (不得;不应该)go the zoo.

③Since you can’t answer the question, I’ll ask someone else.

(2)because表示直接原因,语气最强。Because引导的原因状语从句多放在主句之后。回答由why提出的问题,只能用because。As和since语气较弱,一般用来表示明显的原因。由as和since引导的原因状语从居多放在句首。例如:

①--Why aren’t going there?

--Because I don’t want to.

②As he has no car, he can’t get there easily.

③Since we have no money, we can’t buy it.

(3)because和so不能同用在一个句子里。