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