变否定句方法
1．Be ( 一般现在时is / are / am 一般过去时was/ were ) ， 在be 后面加not .
缩写 ： isn’t aren’t wasn’t weren’t
1）。 She is at home now。 → She is not at home now . = isn’t
2) They are playing basketball 。→ They are not playing basketball 。 = aren’t
3） I am a teacher .→ I am not a teacher 。
4) He was asleep . → He was not asleep . =wasn’t
5)We were happy at the party → We were not happy at the party . weren’t
2. 在情态动词 can ， could ， must ,should ,may ，will , would，shall等后面加not 。
缩写 ： can’t , couldn’t ， mustn’t ,shouldn’t, may not ，won't , wouldn’t ， shalln’t
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1）He can swim in the river 。 → He can not swim in the river .
2)We should clean the room 。 → We should not clean the room .
3）He can read and write． → He can’t read or write．
3. 谓语动词是行为动词时，在该动词前加上don't ／doesn't／didn’t，动词用动词原形.如：1)He gets up early． → He doesn't get up early．
2)They go to school on foot → They don’t go to school on foot 。
3)She saw Liu Xiang yesterday 。 →She didn’t see Liu Xiang yesterday .
He /she / it / Lucy / Li Lei 当主语是第三人称单数时 ， 用 doesn’t
They /we / you/ my parents / I 当主语是复数和第一人称I时， 用don't
当He /she/ it/ Lucy/ LiLei/ They/ we/ you/ my parents/ I 过去时都用
didn't
4。 用含否定意义的词或词组取代肯定句中的某些词或词组。如：
I know both English and Chinese． → I know neither English nor Chinese．
类似的有：ever /always → never somebody → anybody too →
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either
something →anything everybody → no one almost →hardly
already → yet often → seldom Neither…nor → Both 。.。and
5．祈使句的肯定式变否定式
(1）一般在动词前加上 don’t.如： Open the window Don’t open the window．
(2)含有“Let's．．．\"的祈使句,一般用“Let’s not……”
Let’s go there．→ Let's not go there．
6．复合句的肯定句变否定句方法
一般将主句变为否定式。如:I saw her when I left I didn’t see her when I left．
7。 例题
1). I think she is there。 → I don’t think she is there
分析:宾语从句前面的动词是think， believe, expect， suppose .
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→ → ．．
变否定句时， 即否定主句谓语，不否定宾语从句谓语。
2）。 He can sing this song and that one .
He can not sing this song or that one 。
3)。 Tom went to school , too.
Tom didn’t go to school , either.
4）。 He has had supper already .
He hasn't had supper yet 。 助动词has / have / had （not）+ 过去分词
5）。 He had a good rest just now.
He didn’t have a good rest just now。
分析：has / have / had表示开会、吃饭、休息、进行体育锻炼是行为动词，
变否定句时，借用助动词doesn’t / don’t / didn’t ， 后面再接动词原形 。
6）。 Let’s do it。 → L et’s not do it.
7）. He always gets there on time. → He never gets there on time.
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8). It often rains here. → It seldom rains here.
9）。 Be here early tomorrow. → Don't be here early tomorrow。
10）. You had better come。 → You had better not come。
11）。 Both Tom and Xiao Ping went to school。 →
Neither Tom nor Xiao Ping went to school.
8。巩固练习：
1).I think they will fly to Hong Kong tomorrow.
I they fly to Hong Kong tomorrow 。
2)。He has some colour lights,too。
He colour lights，
3).I have to tell her the bad news.
I her the bad news.
4）。She needs some pieces of paper。
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She pieces of paper.
5)。The idea sounds great.
The idea great。
6)。We had a good time at the party。
We a good time at the party.
7）.David has to help his mother in the kitchen。
David to help his mother in the kitchen.
8)。Lily has done that already。
Lily that 。
9）.The evening party had already finished by the time I got there.
The evening party finished by the time I got there。
10).My father can play both baseball and golf。
My father can play baseball golf。
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11).Li Dam and Li Shuang like watching cartoons very much。
Li Dam and Li Shuang don’t like watching cartoons 。
12).Both of his parents teach English in a university.
of his parents English in a university.
13)。My sister and I have once been to Beijing。
My sister and I been to Beijing 。
14）。You’d better go to the hospital to see a doctor.
You’d better the hospital to see a doctor.
15）。We can see somebody sitting under the tree。
We see sitting under the tree。
16)。He does eye exercises every day。
He ___ __ ____ _ eye exercises every day.
17)。I’ve ever been to Beijing three times.
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I ____ _ _____ been to Beijing three times.
18). Lucy will stay there for some time。 → Lucy ____ _ stay there for ___ __ time.
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