英语表示因果推理关系的连词 表示因果推理关系的连词：主要有so, for, then, therefore等。 如The air here is polluted, so the crops are dying. It must be late, for I have been here a long time. 温馨提示：for，because，as，since在用法和意义上的区别： 1 for引导的句子是并列分句，只能后置，并用逗号与前面的句子隔开。主要用来表示推测性原因，或附带解释、说明前一分句的情况。 如The electric current must have been turned off, for the light went out. 2 because用来引导表示直接原因的从句，语气很强，明确地说明因果关系。其引导的从句可置于句首、句末或句中。如He is absent today because he is ill. for引导分句表示因果关系时，它可以和because互换使用。 如上句也可以说成：He is asent today, for he is ill. 但表示推测性原因，就不能互换使用。如He must be ill, for he is absent today. 3 since，as都是不讲自明的原因，是已知的原因，as的语气比since要弱。 如Since (As) you don't feel well, you had better stay at home. 本文来源：https://www.wddqw.com/doc/ebbd2338b4360b4c2e3f5727a5e9856a56122621.html