have to

张文

情态动词－－have to
have to加动词原形
表示"不得不"、"必须"的概念。它比must更含有"客观条件使得必须如此做"的意思，并有较多的时态。如：
Mr. Johnson has to work very hard to earn a living.约翰逊先生为了谋生不得不拼命干活。
I had to leave the party early last night. I wasn't very well.昨晚我只得早点离开晚会，我不大舒服。
We will have to get up very early tomorrow.我们明天必须起得很早。 I shall have to go to the clinic today for my bad cough.我咳嗽得厉害，今天必须去诊疗所看看。
[注]口语中的I have got to，you have got to等：I have to，you have to. Have I got to?和Do I have to?这两种疑问形式均可用。