1、情态动词ha箪滹埘麽ve to 的用法，意思是"必须、不得不"，它侧重于客观上的必要和外界的权威。（1）结构：主语＋have to巯鹧葩宽＋动词原形＋其他（一般现在时，主语是第三人称单数时，用has to；句子是过去时，用had to.）如： We have to wear sneakers for gym class. 在体育课上，我们必须穿运动鞋。Tom has to practice the guitar every day. 汤姆每天必须练习弹吉它。I had to get up at 5:00 am last Monday. 上周一，我不得不早上5点起床。（2）否定形式：主语＋don't have to＋动词原形＋其他一般现在时，主语是第三人称单数时，用doesn't have to. 句子是过去时，用didn't have to）如：Nick doesn't have to wear a uniform. 尼克不必穿制服。We didn't have to do our homework at once. 我们不必马上完成作业。（3）疑问句：Do （Does或Did）＋主语＋have to ＋动词原形＋其他如：Do you have to stay at home on weekends? 周末你必须呆在家里吗？Yes, I do. / No, I don't.是的，我必须。不，我不必。Did he have to go to bed by 11:00 last night? 昨晚，他不得不11点前上床睡觉吗？
