第1个回答 2010-03-06
这种有hard diffcult easy等词
形成 sth is hard/diffcult/easy to时
不定式不用被动
第2个回答 2010-03-06
to do 是不定式的结构表达写法。
这个do是动词的代表,它可以是一般动词,也可以是be动词等。
你记错了,纠正一下。
第3个回答 2012-04-17
不定式定义:由to+动词原形构成。不定式是一种非限定性动词。而非限定动词是指那些在句中不能单独充当谓语的动词,可分为不定式,动名词,现在分词和过去分词。“动词不定式”由动词+不定时构成。动词不定式在句中可以作句子除谓语之外的任何句子成分。动词不定式的被动形式除了一般形式外还有其完成式和进行式。动词不定式可以作以上各种成分,但它毕竟是动词,所以有动词的属性
动词不定式及其短语还可以有自己的宾语、状语,虽然动词不定式在语法上没有表面上的直接主语,但它表达的意义是动作,这一动作一定由使动者发出。这一使动者我们称之为 逻辑主语,其形式如下:
主动形式 被动形式
一般式 (not) to do(not) to be done
进行式 (not) to be doing无被动
完成式 (not) to have done ( not) to have been done
(1)语态
如果动词不定式的逻辑主语是这个不定式所表示的动作的承受者,不定式一般要用被动语态形式。如:
It's a great honour to be invited to Mary's birthday party.(不定式作主语是被动语态to be invited是被邀请)
It was impossible for lost time to be made up.(不定式作主语)
I wish to be sent to work in the country.(不定式作宾语)
Can you tell me which is the car to be repaired?(不定式作定语)
He went to the hospital to be examined.(不定式作状语)
在There be结构中,修饰主语的不定式可用被动,也可用主动。如:There are still many things to take care of (to be taken care of).但有时两种形式表达的意思不同,如:These is nothing to do now.( We have nothing to do now.) There is nothing to be done now.(We can do nothing now.)
(2)时态
1) 现在时:一般现在时表示的动词,有时与谓语动词表示的动作同时发生,有时发生在谓语动词的动作之后。
He seems to know this.
I hope to see you again. = I hope that I'll see you again. 我希望再见到你。
2) 完成时:表示的动作发生在谓语动词表示的动作之前。
I'm sorry to have given you so much trouble.
He seems to have caught a cold.
3) 进行时: 表示动作正在进行,与谓语动词表示的动作同时发生。
He seems to be eating something.
4) 完成进行时:
She is known to have been wreaking on the problem for many years.
一般在情绪后加to do to do 也表将来
[编辑本段][疑问词+不定式结构]
疑问词who,what,which,when,where,whether,how后可接不定式构成不定式短语,在句中作主语、宾语、表 语等。如:
①When to leave for London has not been decided yet. (不定式在句子中做主语)
②Mr. Smith didn't know whether to leave or stay there. (不定式在句子中做宾语)
③I asked Professor Xu how to learn English well. (不定式在句子中做间接宾语)
④The question was where to get the medicine needed. (不定式在句子中表语)
以上例句中疑问词+不定式部分,均可转换为相应的从句形式。如:①When we shall leave…③…how I
could learn…
经常在这种结构中使用的动词有:consider, decide, discover, explain, find out, forget, hear, know, lea rn, observe, understand, wonder等。本回答被提问者采纳
第4个回答 2010-03-08
不定式定义:由to+动词原形构成。不定式是一种非限定性动词。而非限定动词是指那些在句中不能单独充当谓语的动词,可分为不定式,动名词,现在分词和过去分词。“动词不定式”由动词+不定时构成。动词不定式在句中可以作句子除谓语之外的任何句子成分。动词不定式的被动形式除了一般形式外还有其完成式和进行式。动词不定式可以作以上各种成分,但它毕竟是动词,所以有动词的属性
动词不定式及其短语还可以有自己的宾语、状语,虽然动词不定式在语法上没有表面上的直接主语,但它表达的意义是动作,这一动作一定由使动者发出。这一使动者我们称之为 逻辑主语,其形式如下:
主动形式 被动形式
一般式 (not) to do(not) to be done
进行式 (not) to be doing无被动
完成式 (not) to have done ( not) to have been done
(1)语态
如果动词不定式的逻辑主语是这个不定式所表示的动作的承受者,不定式一般要用被动语态形式。如:
It's a great honour to be invited to Mary's birthday party.(不定式作主语是被动语态to be invited是被邀请)
It was impossible for lost time to be made up.(不定式作主语)
I wish to be sent to work in the country.(不定式作宾语)
Can you tell me which is the car to be repaired?(不定式作定语)
He went to the hospital to be examined.(不定式作状语)
在There be结构中,修饰主语的不定式可用被动,也可用主动。如:There are still many things to take care of (to be taken care of).但有时两种形式表达的意思不同,如:These is nothing to do now.( We have nothing to do now.) There is nothing to be done now.(We can do nothing now.)
(2)时态
1) 现在时:一般现在时表示的动词,有时与谓语动词表示的动作同时发生,有时发生在谓语动词的动作之后。
He seems to know this.
I hope to see you again. = I hope that I'll see you again. 我希望再见到你。
2) 完成时:表示的动作发生在谓语动词表示的动作之前。
I'm sorry to have given you so much trouble.
He seems to have caught a cold.
3) 进行时: 表示动作正在进行,与谓语动词表示的动作同时发生。
He seems to be eating something.
4) 完成进行时:
She is known to have been wreaking on the problem for many years.
一般在情绪后加to do to do 也表将来
[编辑本段][疑问词+不定式结构]
疑问词who,what,which,when,where,whether,how后可接不定式构成不定式短语,在句中作主语、宾语、表 语等。如:
①When to leave for London has not been decided yet. (不定式在句子中做主语)
②Mr. Smith didn't know whether to leave or stay there. (不定式在句子中做宾语)
③I asked Professor Xu how to learn English well. (不定式在句子中做间接宾语)
④The question was where to get the medicine needed. (不定式在句子中表语)
以上例句中疑问词+不定式部分,均可转换为相应的从句形式。如:①When we shall leave…③…how I
could learn…
经常在这种结构中使用的动词有:consider, decide, discover, explain, find out, forget, hear, know, lea rn, observe, understand, wonder等。