英语-各种时态肯定句变否定句的诀窍及注意问题
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英语中各种时态肯定句变否定句的诀
窍及应注意的问题
一、各种时态肯定句变否定句口诀
变成否定有规则，
“是” “将”
“有”后加not。
假如没有“是” “有” “将”，
动词前面加don't(
doesn't didn't)。
解释说明：
八种时态由陈述句变成否定句时，陈述句中谓语含有助动词be, have(
has)，
will( shall)的，就在助动词的后面加上not,-般现在时与一般过去时谓语
动词不
含助动词，则在动词前面加上don't或doesn't, didn't。例如:
They are studying English now.
→They are
not studying English now.
They study English.
→They don't study English.
练一练：将下列句子变为否定句。
1. There are some pctures on the front
wall.
has written his composition already.
3. They always go to work early in the
morning,
4. Both of them are good students.
5. All of the students are fouteen years old.
6. Everyone has been to Beijing twice.
7.
The English child can read and write in Chinese.
8. We'll go with him,too.
9. Open the
window ,please.
10. Let's go out for a walk.
11. I think he'll be here soon.
12. Both
Jack and Tom are from England.
13. You'd
better come here earlier next time.
14. I must
hand in my homework now.
答案：
1. There
aren't any pictures on the front wall.
2. He hasnt written his composition
yet.
3. They never go to work early in the
morning.
4. Neither of them is good students.
5. None of the students are fourteen years
old.
6. No one has been to Bejjing twice.
7. The English child can't read or write in
Chinese.
8. We won't go with him,either.
9. Don't open the window ,please.
10. lets
no go out for a ’t let us go out for a walk
11.l don't think he'll be here soon.
12.
Neither Jack nor Tom is fom England.
’d better
not come he earlier next time.
14. l needn't
hand in my homewok now.
二、肯定句变否定句应注意的问题
根据
英语的表达习惯，肯定句变否定句(指完全否定)时，通常只须加上否定副词
not。然而，有些肯定句
改为否定句并不完全遵循这个规则,必须作特殊的变化。
大多数同学每遇到肯定句改为否
定句的题时，总是只按一般常规采取加否定副词
not否定谓语动词的方式来处理。这样就很容易出差错
。所以同学们在做此类型
的题时一定要注意。
1.肯定句中有some，改为否定句时，一般要用any
来替代some。例如:There
are some books on the
desk. -There aren't ary
books on the
desk.(或:There are no books on the
desk. )
解释说明：
some +
bodythingone等构成的复合词，与some的用法相同。例如:
①I have
something important to do.
→I haven't( don't
have ) anything important to do. (或:I have nothing
important to do. )
②There is somebody in
the room.
→There isn't anybody in the room.
(或:There is nobody in the room.）
2.在肯定句中有不作“有”
讲，也不用作助动词用的
have和不作助动词用的do,改为否定句时，须加助动
词do。例
如:
①He has lunch at the school.
→He
doesn't have lunch at the school.
②You had a
good holiday.
→You didn't have a good holiday.
③He does the work by himself.
→He doesn't
do the work by himself.
3.肯定句中的谓语动词是由连系动词(be除外
)担当，
改为否定句时，要用do的相应形式加否定副词not。
例如:
①You
look like a teacher.
→You don't look like a
teacher.
②He becomes a soldier.
→He
doesn't become a soldier.
4.肯定句中有动词seem, appea
r后跟不定式结构,
改为否定句时,无论是采取否定第一个动词，还是否定
不定式，都构成意思
相同的否定句。例如:
Boys seem to like playing.
→Boys don't seem to like playing. ( = Boys
seem not to like playing. )
He appears to have
a wonderful time.
→He doesn't appear to have a
wonderful time. ( = He appears not to
have a
wonderful time. )
5.肯定句中含有连接两个或两个以上的并列成分的连
词and,改为否定句时，一般要将and改为or。例如:
①He can sing and
dance.
→He can't sing or dance.
②I have
brothers and sisters.
→I haven't any brothers
or sisters. (或:I have no brothers or sisters. I
have no brothers and no sisters. I have
neither brothers nor sisters. )
6.肯定句中有too,als
o,改为否定句时，须将too,also
改为either,并把either置于句末，用逗号同句
子分
开。例如:
He is there, too.
→He isn't
there，either.
That shirt also fits me.
→That shirt doesn't fit me，either.
7.肯定句中含有并列连词both. .. and...或not
only...
but also...结构,改为否定句时，要用
neither...
nor...或not... either... or...结构来表示
否定。例如:
①He studied both English and Russian.
→He
studied neither English nor Russian.或He didn't
study either English
or Russian.
②The boy
is not only clever but also diligent.
→The boy
is neither clever nordiligent.或The boy isn't
either clever or
diligent.
8.肯定句中含有频度副词always,改为否定句时，英
语习惯上不说not
always,而用never替代。例如:
Tom always asks the same
question.
→Tom never asks the same question. <
/p>
9.肯定句中含有频度副词often,改为否定句时,通常
将often改为s
eldom(或rarely)。例如:
He often goes home at
seven.
→He seldom( rarely) goes home at seven.
10.肯定句中含有频度副词already，改为否定句时，
通常将already改为ye
t。例如:
They have already seen the film.
→They haven't seen the film yet.
11.肯定句中含有
频度副词nearly,改为否定句时，要
将nearly改为hardly(或scarcely)。
例如: He
nearly knows it.
→He hardly(
scarcely) knows it.
12.肯定句中含有sill,改为否定句时，要将still改为
not….any
longer(或not... any more)。 例如:
①The scientist
still lives .
→The scientist doesn't live
there any longer
②She still cried.
→She didn't cry any more.
13.肯定句中含有情态动词had
better或wouId
rather，改为否定句时，要把定副词not放在had
better或would rather之后，而不是放在had或
would之后。例如:
①You had better start out at once.
→You
had better not start out at once.
②We would
rather have the small one than the large one.
→We would rather not have the small one than
the large one.
14.肯定句中含有情态动词ought
to,改为否定句时，
要把否定副词not放在ought之后，而不是放在to
之后。
①You ought to visit her this evening.
→You
ought not to visit her this evening.
15.肯定句中含有情态动词have
to,改为否定句时，
否定副词not既可放在have之后，也可改为
don't(
doesn't didn't)have to。例如:
My brother had to
finish reading the story -book last night.
→My
brother hadn't to finish reading the story-book
last night.
( = My brother didn't have to
finish reading the story-book last night. )
16.肯定句中含有情态动词used
to,改为否定句时，
否定副词not应放在used之后(即:usedn't
to)，或
者说never used to,一般不说didn't use to。例如:
I used to like the cat.
→I usedn't to like
the cat. (或:I never used to like the cat.)
17.
肯定句中含有情态动词must,改为否定句时，要
按must在句子中确切含义而定。如果must表
示“不
必”,用need not(
needn't);如果must表示“禁止”、
“不允许”,要用must not(
mustn't);如果must表
示“猜测”或“判断”，则用can
not(can't)。例如:
①You must hand in your homework
tomorrow.
→You needn't hand in your
homework tomorrow.
②You must speak loudly in
the library.
→ You musnt't speak loudly in the
library.
③He must have seen the fiIm.
→He
can''t have seen the fiIm.
18.肯定句是祈使句，改为否定句时一般
是在动词原形
前面加do和not(常用其缩写形式don't)。但以let
开头的祈使句.
在改为否定句时，却有两种形式:一种是
在let前加Don't;另一种是在不定式前面加上否定副<
br>词not。例如:
①Stop talking.
→Don't stop
talking.
②Let's go home.
→Let's not go
home,
③③Let's do the work.
→Don't let them
do the work.
19.肯定句中含有both，all，every ，e
verybody，
everyhing等表示总括意义的代词、形容词或副词，
在改为否定句
时，要把上述词分别改为相应的
neither ,none,nobody
,nothing等。否则，就可
能成为部分否定句。例如:
①Both of us
can speak French.
→Neither of us can spealk
French.
②All of the students are going to the
cinema.
→None of the students are going to the
cinema.
③Everybody has seen the flim.
→Nobody has seen the flim.
④He knows
everything.
→He knows nothing. ( = He doesn't
know anything. )
⑤Every student can answer the
question.
→No student(s) can answer the
question.
20.肯定句是由think,
believe,suppose，imagine等表示“信念”或“揣测”
的动词+that-
从句构成的，在改为否定句时，通常否定主句的谓语动词，不否定
从句中的谓语动词。例如:
①I think that he is honest.
→I
don't think that he is honest.
②I believe that
she'll be back soon.
→I don't believe that
she'll be back soon.
练一练：将下列句子改成否定句。
1.
Both of them are party members.
2. Be late for
the meeting.
3. He can speak not only English,
but also Russian.
4. She is always late for
school.
5. Tom often plays fool with his
cassmates.
6. I think he can come in time.
7. All of them speak Japanese well.
8. I
can spell the word, so can my sister.
9. Any
child can read this book.
10. A few students
can answer this question.
答案：
1.
Neither of them is a Party member.
2. Don't be
late for the meeting.
3. He can speak neither
English nor Russian.
4. She is never late for
school.
5. Tom seldom plays football with his
classmates.
6. I don't think he can come in
time.
7. None of them speak Japanese well.
8. I can't spell the word,neither can my
sister .
9. No child can read this book.
students can answer this question.