Unit7语法 情态动词must和have to课件2021-2022学年仁爱科普版七年级英语下册

情态动词 must&have to&should 1 have to:表客观，英文意为不得不 have to的否定，放在前面 must：表主观，大多时候是必须 mustn't 表否定，意思是禁止 情态动词之must和have to 2 must的本意 例句： 1.We must protect our earth. 2.You must obey the traffic rules. must表示必须，后面加动词原形 must的回答 --Must I finish it now? --Yes,you must./No,you needn't/don't have to 回答must的问句，肯定回答用must，否定回答用needn't或者don't have to 特别注意：mustn't不能回答must的疑问句，mustn't是指禁止 知识梳理 3 1.Must I do it now?(否定回答） A.No,you mustn't. B.No,you don’t have to. 2.Must we protect our earth？（肯定回答） A.Yes,we must. B.Yes,we need. 3.Must I do it now?(否定回答） A.No,you mustn't. B.No,you don’t have to. 课堂练习 √ √ √ 4 课堂练习 4.Must I clean the house?(肯定回答） A.Yes,you must. B.Yes,you need. 5.Must I clean the house?(否定回答） A.No,you mustn't. B.No,you needn't. 6.Must they go to school now?(肯定回答） A.Yes,they must. B.No,they need. √ √ √ 5 7.Must she do the homework today?(肯定回答） A.Yes,she must. B.Yes,she need. 8.Must he get up at 6 o'clock？（否定回答） A.No,he mustn't. B.No,he needn't. 9.Must Mike come to the party?(肯定回答） A.Yes,he