一、宾语从句用法
时态： 1．主句用一般现在时,从句可用任意时态.可归纳为“主现从不限” 2．主句用过去时,从句用过去某个时态.可归纳为“主过从四过” 3．主句用过去时,从句是科学真理、客观常识、名人格言时用一般现在时. 4．情态动词could/would用于,“请求”,表示委婉、客气的语气时,从句不受主句的约束.就是主句是一种过去时，从句为各种相应过去时态。He wanted to know what the manager had said at the meeting. He wanted to know who hadn’t passed the exam. He wanted to know when she would leave this building. He wanted to know why she cried last night. He wanted to know where she was going to study. He wanted to know which student was his partner in the short play. He wanted to know if (whether) Tom could play basketball with him that morning. He wanted to know how she managed to solve the problem.在例子中，当主句是过去时态时（一般过去时，过去进行时，过去将来时，过去完成时），从句根据不同情况必须使用过去时态的一种，（大自然的现象和真理除外）。