1.主句是一般现在时,从句根据实际情况使用任何时态。 例如The headmaster hopes everything goes well. 2.主句是过去时态,从句须用过去时态的某种形式。 例如She was sorry that she hadn’t finished her work on time.3.当宾语从句表示的是一个客观真理或者事实时,即使主句是过去时,从句也用一般现在时态。 例如The teacher told his class that light travels faster than sound.