1、Unit 4 语法课堂1.must、mustnt的用法【重点释疑】must是情态动词,后面直接加动词原形。表示“必须”。如：You must go home now.你现在必须回家了。表示坚定的建议。如：You must go to see the doctor.你必须去看医生。表示推测,暗含有很大的可能性,用于肯定句。如：It must be rainy tomorrow.明天肯定要下雨。虽然must表示“必须”的意思,但是用于否定句时,mustnt却表示“不要、不能、禁止”的意思,而不是“不必”。如：You mustnt run on the road.你不能在路上跑。一般疑问句的结构为：
2、Must+主语+动词原形+其他?肯定回答为：Yes,must.否定回答可用：No,neednt.如：Must I finish my homework today?我今天必须完成家庭作业吗？Yes,you must.是的,你必须要完成。/No,you neednt.不,你不必完成。Must they clean the classroom now?他们现在必须打扫教室吗？Yes,they must.是的,他们必须打扫。/No,they neednt.不,他们不必。()【易错示例】Must I finish my homework today?Tomorrow is Saturday.A.Yes
3、,you must.B.No,you neednt.C.No,you mustnt.【易错示例】What do you know about the road (safe)?B2.safe、safety、safely的用法【重点释疑】（1）safe是形容词,意为“安全的”。如：The food is safe for babies.这食品对婴儿来说是安全的。（2）safety是名词,意为“安全”。如：For your safety,please do not get off until the train stops.为了你的安全,请在火车停稳后下车。（3）safely是副词,意为“安全地”。
4、如：How can you cross them safely?你怎么样才能安全地穿过它们呢？road safety是固定搭配,意为“道路安全”。因此这里应该填safety。一、选择方框中的词并用其正确形式填空。（可重复使用）must mustnt neednt cant 1.In the library,you _ keep quiet.must 2._ you see the sign over there?Dont swim in the river.Im sorry.Cant 3.Must I go home now?No,you _.You can play football her
5、e for an hour.neednt 4.What must we not do on the road?We _ play football on the road.mustnt 5.I want to be a good student.I _ listen carefully in class.must 6.Can I park my car in front of the library?No,you _.cant 4.Must Nancy _(wash)clothes now?二、用所给词的适当形式填空。1.You mustnt _(run)on the road.run 2.W
6、e must stay _(safe)on the road and cross it _(safe).safesafely 3.We should pay attention to(注意)medicine _ (safe).safetywash 5.In many big _(city),many people like eating wild animals.cities 6.It brings us many problems.But we _ (should)be afraid of it.shouldnt三、按要求完成句子。1.Must Mike go to see the doct
7、or?(作肯定回答)Yes,_ _.hemust 2.The children must play football on the road.(改为否定句)The children _ _ football on the road.mustntplay 3.We must look at the traffic lights first.(对画线部分提问)_ _ you _ first?Whatmustdo 4.An old woman is crossing the road.(对画线部分提问)_ is _ the road?Whocrossing 5.You cant watch TV now because its late.(对画线部分提问)_ _ I watch TV now?Whycant 6.They must come back before 12 oclock.(改为同义句)They _ _ come back before 12 oclock.haveto
