小升初语法题讲解-第12章：助动词和情态动词（5）have to .docx

5.have to have（has）to与must一样，表示“必须”的意思，两者的区别参见第154页《比较：must 与 have to》。 1) have to的用法 I have to get up early tomorrow morning. 我明天早晨必须（不得不）早起。 1.have（has）to +动词原形 have（has）to后面要用动词原形。当主语为第三人称单数时用has to～，当句子是过去时用had to～。 We have to leave now. 我们不得不现在就离开。 He has to work on Sunday. 他不得不在周日工作。 I had to do my homework last Sunday. 上周日，我不得不做作业。 2) have to的否定句 句型：主语+don't（doesn't）have to+动词原形～. You don't have to walk so fast. 你不必走那么快。 He will not have to buy a new coat next year. 明年，他没必要买新外衣了。 3) have to的疑问句 句型：Do（Does）+主语+have to +动词原形～？ Do you have to study maths now？ 你现在必须学数字吗？ Yes，I do.是的，必须学。 No，I don't（have to）.不，不必学。 Did he have to ask the question？ 他非要问那个问题吗？ Yes，he did.是的。 No，he didn't（have to）.不。 have to 练习题 词形转换 1．You must wash the dishes. =You____ ____ wash the dishes. 2．She can cook well. =She ____ ____ ____ cook well. 3．Wash your face at once. =You ________wash your face at once. 4．They couldn't find any secrets（秘密）. =They ____ not ____ to find any secrets. 5． You should be here on time. =You ____ ____ be here on time. 【答案】 1．have to 2．is able to 3．must 4．was, able 5．ought to