名詞和主謂一致
一、 名詞的分類
英語中名詞主要可以分為可數(shù)名詞和不可數(shù)名詞。
1.可數(shù)名詞
可數(shù)名詞一般都有單復(fù)數(shù)。單數(shù)時,名詞前可加不定冠詞a/an;復(fù)數(shù)時,前面可加數(shù)詞,名詞本身要改成復(fù)數(shù)形式。
可數(shù)名詞的復(fù)數(shù)有規(guī)則和不規(guī)則兩種變化。規(guī)則的名詞,只要在單數(shù)名詞之后加“s”,“es”或去“y”加“ies”就行,如:anumbrella, twelve umbrellas;a factory, threefactories。不規(guī)則的名詞變化則要靠積累記憶,如:a mouse, ten mice;a policeman, sixpolicemen。
有少數(shù)可數(shù)名詞,如sheep,works(工廠),Chinese等,它們的單復(fù)數(shù)同形:a sheep, four sheep;achemical works, five chemical works。
此外,還有一些可數(shù)名詞只有復(fù)數(shù)形式,如clothes,trousers,cattle,police,people(人,人民)等。
英語名詞中還有一些合成詞,它們的復(fù)數(shù)形式有三種可能:1)后面的部分變成復(fù)數(shù)形式:grown-ups,boystudents,grandchildren。2)前面的部分變成復(fù)數(shù)形式:passers-by,lookers-on,sons-in-law。3)前、后都變成復(fù)數(shù)形式:mendoctors,women drivers。
2.不可數(shù)名詞
不可數(shù)名詞沒有單復(fù)數(shù)的變化,前面也不能加a/an,或數(shù)詞。但是我們可以用量詞來表示不可數(shù)名詞的數(shù)量,單復(fù)數(shù)表現(xiàn)在量詞上,如:apiece of paper;two pieces of paper。
在有些情況下,不可數(shù)名詞也可用a/an,表“一種”、“某種”的意思,如have a wonderful time,receive agood education,be made into a fine paper。
有時為了表示量大,不可數(shù)名詞的后面也可加“s”,如sands,ashes,waters等。
但是我們在學(xué)習(xí)不可數(shù)名詞的時候,特別要記住英語中有一些名詞,它們無論在什么情況下,前面都不能用a/an,后面也不可加“s”,如weather,information,等。
3.有的名詞既可是可數(shù)名詞,也可是不可數(shù)名詞
英語中有相當(dāng)一部分的名詞,既可以是可數(shù),也可以是不可數(shù),它們的意義有時略有不同,有時則完全不同。如:difficulty,success, time, work,paper,glass,等。
4.用于表示可數(shù)與不可數(shù)名詞的數(shù)量“多”“少”的常用詞和詞組
跟可數(shù)名詞連用的如:few, a few, many。
跟不可數(shù)名詞連用的如:little, a little, much。
可數(shù)與不可數(shù)都能用的是:a lot of , plenty of。
二、主謂一致
1.通常被看作單數(shù)的主語部分
1)不定式、動名詞和主語從句。
eg.. To see is to believe.
Seeing is believing.
What he said was different from what he did.
2)表示“時間”“距離”“金錢數(shù)量”的名詞。
eg. Twenty years is quite a long time.
10kilometers doesn’t seem to be a long distance to Mira.
300 dollarsis too much for this old coin.
3)數(shù)學(xué)式子。
eg. Two plus five is seven.
4)書報雜志、國家、單位的名字。
eg. The Times is published daily.
The United States is a big country.
5)前面用a kind of, a sort of或this kind of, this sort of等詞組的名詞。
eg. This kind of tree(s) often grows well inwarm weather.
6)代詞either, neither作主語。
eg. Either of the plans is good.
Neither of them was carrying a weapon.
7)many a/ more than one 加單數(shù)名詞,或one out of加復(fù)數(shù)名詞作主語。
eg. Many a young man has tried and failed.
More than one employee has been dismissed.
One out often thousand computers was infected with the virus.
2.通常被看作復(fù)數(shù)的主語部分
1)一些只有復(fù)數(shù)的名詞如clothes, trousers, police等。
eg. These trousers are dirty.
但要注意比較:A new pair of trousers is what you need。
2)代詞both作主語。
eg. Both of them have received higheducation.
3.需要進(jìn)行分析才能確定的主語部分
1)代詞all, some,作主語。
所代的名詞是可數(shù)名詞,就看作復(fù)數(shù);是不可數(shù)名詞,就看作單數(shù)。
eg. All is ready. (= Everything is ready.)
All are present. (= All the people/students... are present.)
2)a lot of, lots of, plenty of, some, any, 20% of, halfof...等詞組作主語。
所修飾的名詞是可數(shù)名詞,就看作復(fù)數(shù);是不可數(shù)名詞,就看作單數(shù)。
eg. 70% of the surface of the earth is coveredwith water.
90% of the graduates from the high school go to university.
3)關(guān)系代詞who, which, that作主語。
由先行詞決定單、復(fù)數(shù)。
eg. The student who is talking with theprincipal is Tom.
The students who have chosen physics will have a testtomorrow.
但要注意one of ...與only one of...所修飾的先行詞。
eg. He is one of the students in our class whohave been to Beijing.
He is the only one of the students who has been to London.
4)一些表示集體意義的名詞如family, team, class等。
當(dāng)這些名詞強(qiáng)調(diào)的是一個整體時,看作單數(shù);當(dāng)它們強(qiáng)調(diào)的是這個集體中的成員時,看作復(fù)數(shù)。
eg. Happy families are all alike; every unhappyfamily is unhappy in its own way.
My family are all early risers.
4.出現(xiàn)在句首,用連詞或介詞連接的兩個名詞或詞組
1)用both...and...連接的兩個名詞看作復(fù)數(shù)。
Both Kate and Jean are football players.
2)用or, either...or..., neither...nor..., not only...butalso...連接的兩個名詞,由靠近動詞的名詞決定單復(fù)數(shù)。
Either you or I am to go.
Not only the students but also the teacher hasto observe the rules.
3)用as well as, (together) with, like, besides, but,except等連接的兩個名詞,由第一個名詞決定單復(fù)數(shù)。
eg. His eyebrows as well as his hair are nowwhite.
No one but these two peasants has been there.
實際上這些都是介詞短語提前,不是并列的主語。
4)用and連接的兩個名詞有幾種情況:
a)看作復(fù)數(shù)。
eg. Tom andMary are primary pupils.
b) 在有every ... and every ..., each ... and each... 的時候;或用and連接的兩個名詞表示的是一件東西或一個人時,看作單數(shù)。
eg. Every boy and every girl in our country hasthe right to go to school.
Bread andbutter is what he eats for breakfast every day.
動詞的時態(tài)與語態(tài)
一、動詞的時態(tài)
英語的動詞可以有十六種變化,但現(xiàn)在常用的是十二種,其中有九種是高中學(xué)生必須掌握的,還有三種只要理解。現(xiàn)以動詞do為例,十二種時態(tài)的形式列表如下:
一般 進(jìn)行 完成 完成進(jìn)行
現(xiàn)在 do/does is/am/aredoing have/has done have/has been doing
過去 did was/weredoing haddone *hadbeen doing
將來 shall/willdo *shall/will bedoing *shall/will havedone
過去將來 woulddo
(打星號的為理解項目)
1.一般現(xiàn)在時態(tài)
A)意義:現(xiàn)階段經(jīng)常反復(fù)發(fā)生的動作或現(xiàn)在的狀態(tài)。
eg. He gets up at six every morning.
There is a big tree in the back yard.
B)常用的時間狀語:always, often, usually, sometimes,seldom, never, every day, once a week,等。
C)表示一種真理、自然規(guī)律等,在間接引語中也仍然用一般現(xiàn)在時態(tài)。
eg. The scientist explained that the earth goesround the sun, but no one believed him then.
D)在時間、條件等狀語從句中,代替將來時。
eg. If he is not busy, he will come to the partytomorrow.
E)注意第三人稱單數(shù)時,動詞后面要加“s”。
2. 一般過去時態(tài)
A)意義:過去的動作或狀態(tài)。注意,即使是剛剛發(fā)生的事情,時間非常短,也要用過去時態(tài)。如:Why!It’s you—Mary! I didn’t know you were here!
B)常用的時間狀語:yesterday, last week, 3 years ago, justnow, 等。
C)動詞過去式的規(guī)則變化(加ed)和不規(guī)則變化。
3.一般將來時態(tài)
A)意義:將來要發(fā)生的動作或狀態(tài)。
B)常用的時間狀語:tomorrow, next moth, in two weeks, 等。
C)除了用shall/will之外的將來表達(dá)法:
a) is/am/are going to do,意為“打算、準(zhǔn)備、馬上就要”。
eg. It’s going to rain.
b) is/am/are to do,意為“(計劃好/安排好)要......”
eg. The new underground railway is to be openedto traffic next year.
c)is/am/are about to do,意為“馬上就要”。
eg. Hurry up! The plane is about to takeoff.
d)某些動詞(主要是一些表示位置移動的動詞)可用一般現(xiàn)在時態(tài)或現(xiàn)在進(jìn)行時態(tài)表示將來的動作。
eg. The train leaves for Beijing at 8:30 thisevening.
He is going to London next week.
4.現(xiàn)在進(jìn)行時態(tài)
A)意義:表示在說話的同時或最近一個階段正在發(fā)生的動作。
B)常用的時間狀語:now, these days, at present, at themoment, 等。
C)有時可以和always, constantly,forever等時間狀語連用,表示說話人的某中特殊的感情。
eg. He isalways thinking of others.
Mrs Smith is constantly quarrelling with her neighbours.
D)有些瞬間動詞可以用進(jìn)行時態(tài)表示“馬上就要......”
eg. The old man isdying.
E)英語中有些表示狀態(tài)、感覺、心理活動的動詞沒有進(jìn)行時態(tài),如know, understand,believe, like, love, see, hear, seem, 等等。
5.過去進(jìn)行時態(tài)
A)意義:表示過去某個時刻正在做的動作。
B)常用的時間狀語:this time yesterday, at 9:00 lastnight, 等。
C)有些動詞(主要是一些表示位置移動等的動詞和瞬間動詞)的過去進(jìn)行時態(tài)可以表示過去將來的意義。
eg. I wastold that she was leaving for Australia the next morning.
*6.將來進(jìn)行時態(tài)
A)意義:表示將來某個時刻正在發(fā)生的動作。
B)常用的時間狀語:this time tomorrow, at 9:00 next Sundaymorning, 等。
eg. What will you be doing at9:00 on June 7next year?
7.現(xiàn)在完成時態(tài)
A)意義:a. 表示過去某個時刻開始,一直持續(xù)到現(xiàn)在的動作或狀態(tài)。(只有部分延續(xù)性動詞,如live, work, study,等可以表示這一意義)
eg. I have lived in Shanghai since I was born.