一、条件状语从句
条件状语从句是用于表示主句动作发生的前提或条件的从句。通常由下列从属连词和短语来引导:if(如果,假如),unless(除非),as(so) long as(只要),provided/providing(that)(只要),suppose/supposing(假设),on condition (that)(如果),in case(以防)等。 We’ll come over to see you on Wednesday if we have time. 如果有空,我们星期三来看你。 You can borrow my car as long as you promise not to drive too fast. 你可以借用我的车只要你承诺不开快车。