情态动词的用法

情态动词的用法情态动词的用法 1 May might 用法有二 用法有二 表示可能性 may 可能性 might 可能性 Eg I t may might be snowy tomorrow 表示请求 可以 一般疑问句的回答 肯定回答一般是 Yes please Sure Certainly Of course 等 否定回答一般是 No you can t mustn t Eg May I stop here No you mustn t 达标练习达标练习 1 May I go out to play basketball Dad No you You must finish your homework first A mustn t B may not C couldn t D needn t 2 May I stop here No you A can t B might not C needn t D won t 2 must have to 必须 否定词 mustn t 不允许 禁止 don t have to 不必 needn t must 引导的一般疑问句 肯定回答用 must 否定回答用 needn t 或 don t have to Eg Must I do homework Yes you must No you needn t must 还表示推测 一定 肯定 Eg You must be the new teacher 达标练习达标练习 1 Could I borrow your dictionary Yes of course you A might B will C can D should 2 Look Mr li is in the library It be him He has gone to Beijing A mustn t B can t C shouldn t D won t 3 In china when someone gives you a present you 不可以 open it immediately 4 You 必须 wait and open it later 5 If you are late for class you should say 可以 I come in please 6 We are students We 必须 go to school from Monday to Friday But we 不必 go to school on Sunday 7 Man 不能 live without water and air must 和和 have to 的区别的区别 8 两词都是 必须 的意思 have to 表示客观的需要 must 表示说话人主观上的必要 9 My brother was very ill so I had to call the doctor in the middle of the night 我弟弟病得 很厉害 我只得半夜里把医生请来 客观上需要做这件事 He said that they must work hard 他说他们必须努力工作 主观上要做这件事 10 在否定结构中 don t have to 表示 不必 mustn t 表示 禁止 11 You don t have to tell him about it 你不一定要把此事告诉他 You mustn t tell him about it 你一定不要把这件事告诉他 12 情态动词 can 和 may 都能表示 可能性 如 He may be right 他可能对 He can t be right 他不可能对 13 一般说来 can 多用于疑问句和否定句 表示怀疑或不相信等态度 而 may 则多用于 陈述句 表示一种揣测 14 二者表示的语气不同 在否定句中 can t 表达的否定语气较强 意为 不可能 而 may not 表达的否定语气较弱 意为 可能不 或 也许不 That cannot be true That may not be true 15 根据以上分析 我们可以归纳为三条原则 1 在肯定句中用 may 不用 can 2 在疑问句中用 can 不用 may 3 在否定句中 若语气肯定 表示 不可能 时用 cannot 若语气不肯定 表示 可能 不 时用 may not 16 Must I start at once No you A needn t B mustn t C can t D won t 17 Could I borrow your dictionary Yes of course you A might B will C can D should 18 the news be true No it be true A Can can t B May can t C May may not D Must mustn t 19 I try out all the ideas No you A Must m