must变否定是什么,变一般疑问句是什么?

如题所述

1,must做比须时,否定是must not或mustn't;表示推测时,通常与be连用,否定用can't be

2,must做比须时,反义疑问句用mustn't;如You must obey the school rules,mustn't you?
表示推测时,要用be或助动词do的相应时态;如:Tom must be in the school room now,isn't he?
Tom must have arrived yesterday,didn't he?
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第1个回答  2013-04-30
must变否定句,只需要在 must 后面直接加not ,变为 must not 缩写为mustn't;
变疑问句,直接将must提到句首追问

说错了,是变否定和反义疑问

追答

当陈述部分有情态动词must,问句有4种情况:
(1)mustn't表示“禁止,不可,不必”时,附加问句通常要用must.
You mustn't stop your car here,must you?
你不能把车停在这地方,知道吗?
(2)must表示“有必要”时,附加问句通常要用needn't.
They must finish the work today,needn't they?
他们今天要完成这项工作,是吗?
(3)当must用来表示对现在的情况进行推测时,问句通常要根据must后面的动词采用相应的形式。
He must be good at English,isn't he?
他英语一定学得很好,是吗?
(4)当must+have done表示对过去的情况进行推测(一般句中有明确的过去时间状语),问句要根据陈述部分谓语的情况用“didn't+主语”或“wasn't/weren't+主语”;如果强调动作的完成(一般没有明确的过去时间状语),问句要用“haven't/hasn't+主语”。
She must have read the novel last week,didn't she?
她上星期一定读了这本小说,是吗?
You must have told her about it,haven't you?
你一定把这事告诉她了,是吗?

追问

我记着好像有一个needn't吧

追答

回答must引出的问句时,如果答案是否定的回答,不能用 mustn't ,而要用needn't或don't have to.
例句:Must I return the book tomorrow? no,you needn't.

第2个回答  2013-04-30
Must变否定直接加not,
变一般疑问Must提至句首,回答Must或Don't have to
第3个回答  2013-04-30
否定是must not 吧