到目前为止,我们主要学习了三类动词:be动词、情态动词和实义动词。下面我们分别来讲一下它们得用法。
be动词属于系动词, 在句子中主要表现为三种形式:am is、are。后面往往接形容词或名词做表语。如:
I’m young. (young形容词做表语)
He is a boy. ( a boy名词做表语)
含有be动词的句子在进行否定、疑问句变化时,都要在be动词上变化。
变为否定句:主语+be+ not+其他。即,直接在be后not.
①I’m a Chinese boy.(变为否定句)
②You are good. (变为否定句)
③He is strict with us. (变为否定句)
④She is from America. (变为否定句)
以上四个句子中都含有am、 is或are,变否定句时,直接在am 、is、are后面加上not.即:
①I’m not a Chinese boy.
②You are not good.
③He is not strict with us.
④She is not from America.
变为一般疑问句:Be+主语+其他?即把be动词提到主语的前面。注意:当肯定句主语为第一人称I和We时,变一般疑问句要变为第二人称,be动词也要相应的变为are.同样肯定句中的my和our 也要变为your.
I am a boy. (变为一般疑问句)
→Are you a student?
We are good friends. (变为一般疑问句)
→Are you good friends?
She is from America. (变为一般疑问句)
→Is she from America?
He is strict with us. (变为一般疑问句)
→Is he strict with us?
变特殊疑问句:一般的要求为“对划线部分提问”,即用特殊疑问词代替划线的部分,后接省略划线部分的一般疑问句(一般不再出现划线部分)。如:
I’m well.(对划线部分提问)
→How are you?
②She is from America. (对划线部分提问)
→Where is she from?
关于情态动词:初中我们常用的情态动词主要有:can、 may、must、need。我们这里主要以can为例来说明情态动词的用法。情态动词后面必须接动词的原形。情态动词can的用法类似于be动词。不论主语为第几人称,变否定就是在can后加not.变疑问就是把can提到句子前面。
变否定句:主语+can +not+ 其他。
①I can spell my name.(变否定句)
拆分→I can not(can’t)spell my name.
②He can swim. (变否定句)
→He can’t swim.
变一般疑问句:Can + 主语+ 其他?即直接把can提到句首。
I can spell my name. (变为一般疑问句)
→Can you spell your name?
He cans swim.(变为一般疑问句)
→Can he swim?
变特殊疑问句:特殊疑问词+一般疑问句?
I can spell my name. (对划线部分提问)
→What can you spell?
He can swim. (对划线部分提问)
→Who can swim?
3.实义动词,也叫行为动词。就我们现在所学的内容来讲,实义动词所在的句子中一般不存在be动词。也就是在含有实义动词的句子变否定句或疑问句时,一定不能用be动词。那么,实义动词究竟怎样用呢?正如be动词随着主语的变化可变为am、is、are一样,实义动词在肯定句中,也要随着主语的变化而变化。当主语为第三人称单数he, she, it时,实义动词要变为相应的第三称单数;当主语为非第三人称单数I, you(你), we, you(你们) they时,实义动词要用动词的原形。而在变否定句和疑问句时,不能直接在动词上变,而是要借助另一类动词:助动词do、does。
肯定句:
I have a blue book.
He has a brother.
She wants to be a teacher.
They like to play basketball.
(2)否定句:主语+don’t/doesn’t+动词原形。其中do/does为助动词,是来帮助实义动词构成否定或疑问句的,但加了do/does后,其后面的动词必须用动词原形。
I have a blue book.(变为否定句)
→I don’t have a blue book.
He has a brother. (变为否定句)
→He doesn’t have
She wants to be a teacher. (变为否定句)
→She doesn’t want to be a teacher.
They like to play basketball. (变为否定句)
→They don’t like to play basketball.
一般疑问句:Do/Does +主语+动词原形+其他?句中加了do/does后,其后面的动词还是必须用动词原形。
I have a blue book. (变为一般疑问句)
→Do you have a blue book?
He has a brother. (变为一般疑问句)
→Does he have a brother?
My brother does his homework before supper. (变为一般疑问句)
→Does your brother do his homework before supper?
She wants to be a teacher. (变为一般疑问句)
→Does she want to be a teacher?
They like to play basketball. (变为一般疑问句)
→Do they like to play basketball?
特殊疑问句:特殊疑问词+一般疑问句?
Your sister likes English best because it’s interesting. (对划线部分提问)
→Why does your sister like English best?
He does his homework before supper. (对划线部分提问)
→When does he do his homework?
注意:当含有and引导的短语在句中做谓语或宾语,我们把这类句子变否定句时,必须把and变为or.如:
He can swim and dance. (变为否定句)
→He can’t swim or dance.
My father likes English and math. (变为否定句)
→My father doesn’t like English or math.