5.不定式、动名词和分词作定语时的区别
①不定式——表示未来发生的动作。
过去分词——表示动作已经完成。
现在分词——表示动作正在进行。例如:
The meeting to be held next week is very important.(下周举行的)
The meeting held last week is very important.(上周举行的)
The meeting being held now is very important.(正在举行的)
②动名词与现在分词作定语时的区别如下:
例如:a sleeping child (a child who is sleeping)
a sleeping car (a car for sleeping)
③动名词作定语时,只能放在所修饰的名词之前,而分词作定语时可以放在所修饰的名词之前或之后。例如:
on the day following (=on the following day)
an old spelling book (不可换成an old book spelling)
6.现在分词与过去分词的区别
(1)(定语)the girl sitting under the tree；the language spoken in Japan (主、被动之别),a falling tree,a fallen tree (动作所处的阶段不同)
(2)(状语)Helping others,he felt quite happy.(主、被动之别)
Helped by a boy,we found the school with no difficulty.
(3)(表语)English is interesting.I am interested in English.(主、被动之别)
(4)(宾补)I heard her singing this song.
I heard this song sung.(主、被动之别)
7.不定式、分词与动名词作表语时的区别
1)不定式与动名词作表语时的区别
不定式作表语——表示某一次具体动作。
动名词作表语——表示比较抽象的一般行为、习惯。
My favorite sport is swimming.我最喜欢的运动是游泳。
The first thing for us to do is to improve our pronunciation.我们要做的第一件事是提高我们的语音水平。
2)现在分词与动名词作表语的区别如下:
(1)看主语是否是-ing动词的执行者(即-ing动词的动作是否是句子主语的动作)。是,则为分词,不是,则为动名词。例如:
①He is cleaning the street.他正在打扫大街。
②His job is cleaning the street.他的工作是打扫大街。
例①中的clean是主语he的动作,为分词。例②中的clean显然不是his job的动作,为动名词。
(2)看-ing动词(结构)能否与主语对换位置。能者为动名词,不能者则为分词。例如:
③The most difficult problem is building the bridge base.
④They are building the bridge base.
例③可以调整为:“Building the bridge base is the most diffi-cult.”,故为动名词。而例④则不能(Building the bridge are they.不正确),故为分词。
(3)看是否能用程度副词quite,very来修饰。能则为分词,不能则为动名词。例如:
This book is (very/quite)moving.
His job is teaching maths.(不能添加very,quite)
8.to的省略与保留
构成不定式的小品词to,你可别小视它,也别随意“去”、“留”它,不然的话,你可要犯错误的啦!为帮助同学们避免此类错误,现将其这两方面的用法归纳如下:
1.to可省略的情形
(1)两个以上并列的不定式,除第一个带to之外,其余的通常省略to。例如:
He wants to sell his old house and buy a new one.他想卖掉旧房子,买幢新房子。
The teacher told us to come into the lab,wear the special gloves and do the experiment separately.老师叫我们进入实验室,带上特种手套,然后各自做这个实验。
但若强调比较意义时,则to不能省略。例如:
It is easier to say than to do.说比做要容易。
I came here to ask for help,not to give help.我是来这儿求助的,而不是来援助的。
I haven't decided to go home or to stay at school this summer.我尚未决定今年夏天是回家还是留校。
(2)在see,watch,notice,observe,look at,make,let,have,listen to,hear,feel等动词的主动结构中用作宾补的不定式,应省略to。例如:
I saw him go into the hall.我看见他走进大厅。
Who made you do that?谁让你干那个?
但在这些词(除watch,notice,have不能用之外)的被动式中,则需要补出to,不能省略。例如:
She was heard to sing the song in English.有人听见她用英语唱这首歌。
I was allowed to leave only after twelve hours.十二个小时后,我才被允许离开。
(3)用作连系动词be的表语的不定式,如其前有行为动词do,可省略to;如无do,则不能。例如:
The first thing for them to do is collect enough money.他们要做的第一件事是筹集足够的资金。
His wish is to be a doctor when he grows up.他的愿望是长大后做名医生。
(4)在would rather,had better,used to,have to,ought to,be able to,be going to等词组或结构后应接省略to的不定式。例如:
I would rather have stayed at home last night.我倒宁愿昨晚是呆在家中。
They used to play football on the sand by the river.他们过去常到河边的沙地上踢球。
(5)用在but,except,besides等介词后作宾语的不定式,如其前有行为动词do,可省略to;如无do,则不能省略to。例如:
Mary did nothing except clean her clothes.玛丽什么也没有做,只洗了她的衣服。
I had nothing to do besides answer their questions then.我当时别无选择,只有回答他们的问题。
He desired nothing but to succeed.他别无他求,只想成功。
They had no choice but to wait.他们别无选择,唯有等待。
(6)用在help后作宾语的不定式通常可省略to。例如:
Reading can help enlarge your vocabulary.阅读有助于扩大你的词汇量。
用在help后作宾补的不定式可带to或不带to。例如:
Who can help him (to)carry this box?谁能帮他拎一下这个箱子?
(7)在can't but,can't help but,can't choose but等短语之后一般接不带to的不定式。例如:
There was no bus that day.I couldn't choose but stay there for an-other night.那天没有公共汽车,我别无选择,只好在那儿再呆了一个晚上。
2.to应保留的情形
为了避免重复或使语言简洁,有些情况下,不定式to后的动词部分可以省略,而只将其标志to予以保留,以代替不定式充当相应的句子成分。这些情形有:
(1)用在afford,aGREe,expect,fail,forget,hope,intend,(would)like,love,mean,plan,prefer,promise,refuse,try,want,wish等动词后作宾语的不定式
—Why didn't you come to see me last night?你昨晚为何不来看我?
—I had intended/meant to,but an old friend came.我本打算来,但来了位老朋友。
She didn't join in the game though she had promised to.她没有参加比赛,尽管她曾答应过。
在某些个别情况下,to可以保留或不保留。例如:
He says he would come as soon as he has got a chance (to).他说他只要有机会就立即来。
在少数句子中通常不带to。例如:
You may go if you like.只要你愿意,你就可以去。
(2)用在afraid,angry,foolish,glad,happy,lucky,pleased,sur-prised,wrong等形容词后作状语的不定式
A lot of people won a little prize,but I was not lucky to.很多人赢得一个小礼品,但我却没有这样的好运。
All classmates succeeded in jumping over the wall,but she was still afraid to.所有的同学都成功地跳过墙,但她还是不敢跳。
(3)用在“疑问词+不定式”结构中的不定式
She wants to buy a new bike,but she doesn't know which to.她想买辆新自行车,但不知买哪辆车好。
I would help you mend your TV set,if I knew how to.如果我知道怎么修,定会帮助你修好你的电视机。
(4)用在allow,ask,expect,forbid,force,invite,order,permit,per-suade,tell,warn等词后作宾补的不定式
I went there because my teacher asked me to.我到那儿去,是因为老师叫我去。
He stole because his uncle forced him to.他偷窃是因为他叔叔逼迫他那样干。
当这些句子变为被动句时,也同样可以。例如:
She said she would come and join us if she was invited to.她说只要被邀请,她就会来加入我们。
You can't kill anybody even though you are ordered to.即使有人命令你杀人,你也不能这样做。
