had to do 是什么时态

　　had to的例句：

　　I had papers relating to the children which my wife and I had to sign.

　　我有一些关于孩子的文件需要我和妻子签字。

　　I had to keep in with the people who mattered.

　　我得和管事儿的人保持良好关系。

　　I felt I had to give him a chance.

　　我觉得自己必须给他个机会。

　　One onlooker had to be restrained by police.

　　一个旁观者遭到了警察的制止。

　　had to 与have to用法的区别

　　用法没有任何不同，只是时态不同。had to 是一般过去时，have to 是一般现在时。

　　had to和have to都是“不得不”的意思，但是：had to是一般过去时态，

　　比如：It was rainy, so I had to stay at home yesterday.

　　昨天下雨了，所以我不得不呆在家。

　　have to是一般现在时态，比如：You have to finish your homework before you watch TV.

　　你必须先完成作业再看电视。