初中英語語法重難點集匯

編輯: 逍遙路 關(guān)鍵詞: 初中英語 來源: 高中學(xué)習(xí)網(wǎng)

(一) 主謂一致
主謂一致是指一個句子的主語和謂語動詞保持?jǐn)?shù)的一致關(guān)系。一個句子中主謂一致,通常指三個基本原則:一致,即形式上一致;概念一致,即概念或意念上的一致;毗鄰一致,即謂語動詞的形式與鄰近的名詞一致。
一、 語法一致原則
1、 在通常情況下,一個句子的主語和謂語在語法形式上保持一致。即主語為單數(shù)形式,謂語也為單數(shù)形式;主語為復(fù)數(shù)形式,謂語也為復(fù)數(shù)形式。如:
This exercise on English idioms is not easy.這個短語練習(xí)不容易。
2、 在“there be”結(jié)構(gòu)中, “be”的單復(fù)數(shù)取決與后面主語的數(shù).如:
There has been little change in this city.這個城市沒有多少變化。
3、“one of”結(jié)構(gòu),位于用單數(shù),“two of”結(jié)構(gòu)位于用復(fù)數(shù)
One of the things I want to do is traveling.我想做的一件事是去旅行。
Two of the boys have lost their way home.有兩個男孩回家迷路了。
3、 倒裝句的主語在謂語之后,避免誤用。
Never before has she been to Paris!她以前從未去過巴黎。
二、 概念一致
1、 主語是抽象概念、短語或從句,謂語用單數(shù)形式。如:
To tell lies is wrong.說謊是不正確的。(不定式做主語)
Keeping the house is a tiring job.管理家務(wù)是一件很勞累的事。(動名詞做主語)
How this happened is not clear to anyone.(從句做主語)
注意:
(1) 用what或which引導(dǎo)的主語從句或簡單句中的數(shù)的概念取決于后面的表語,因為它們在邏輯上的意義是相同的。如:
Which is your seat?你的座位是哪一個?
Which are your seats?你們的座位是哪些?
(2) 單個的分詞作主語,不定式作主語,以及主語從句,謂語都用單數(shù),若用連接上述的相同兩個成分,謂語才用復(fù)數(shù)。
2、 兩個或兩個以上的主語用and和both連接時,謂語用復(fù)數(shù)形式。
3、 and連接的并列主語指同一人或同一樣?xùn)|西,and后的名詞前沒有冠詞,謂語用單數(shù);若有,則用復(fù)數(shù)。如:
My best friend and adviser has changed his mind again.我的密友兼顧問又改變他的想法了。
My friend and the student Sue are in the classroom.我的朋友和那位叫蘇的同學(xué)在教室里。
a. 若and后面加not,謂語用單數(shù)。如:
Lilei,and not I, has won the game.是 Lilei贏了比賽,而不是我。
b. 用and 連接的單數(shù)主語,前面有each,every,many a,no等詞修飾時,謂語用單數(shù)。
c. 復(fù)數(shù)主語前加each,謂語仍用復(fù)數(shù)。
d. no后面名詞為單數(shù),謂語用單數(shù);后為復(fù)數(shù),謂語用復(fù)數(shù)。
三、 毗鄰一致
由not only…but also,neither…nor…,either…or…,or 連接的并列主語,在肯定句中謂語變化取決于后面的餓主語,在疑問句中取決于前面的主語。如;
Either he or I am mistaken.他和我都沒錯。
Either he or you are to go there.不是他就是你要到那兒去。
(詳見下冊P155~P156)
(二) 虛擬語氣
虛擬語氣表示說話人的愿望、假設(shè)、猜測或建議,而不是事實。虛擬語氣是通過句中的謂語動詞的特殊形式來表現(xiàn)的,因此,掌握虛擬語氣中的各種謂語動詞的形式變化,是掌握虛擬語氣的關(guān)鍵。
一、 虛擬語氣在簡單句中的用法
虛擬語氣用于簡單句中,一般表示祝愿、命令等。謂語動詞要用原形。
二、 虛擬語氣在主從復(fù)合句中的用法
(1) 在狀語從句中的用法
1、 條件句中的用法
虛擬語氣的條件句是用謂語動詞的特殊形式來表現(xiàn)與現(xiàn)在、過去事實相反的情況或?qū)戆l(fā)生的情況表示懷疑,和直陳語氣條件句中的謂語動詞形式以及表達(dá)的含義完全不同。虛擬語氣條件句中所用的謂語動詞的過去時、過去完成時、過去將來時等,只表示不同的虛擬語氣,和直陳語氣的過去時、過去完成時、過去將來時等毫無關(guān)系。
現(xiàn)將虛擬語氣的各種具體形式和用法分述如下;
a. 表示與現(xiàn)在事實相反的情況
①形式
條件從句的動詞形式 主句的動詞形式
If I (we,you,he,she,it,they)+行為動詞的過去式(be的過去式一般用were) I (we) should
You (he,she , +動詞原形或:
they,it ) would

所有人稱+might(could)+動詞原形
②用法:
If I had more time, I should study German.(fact:I have no more time, so I shall not study German. )
If she were not so busy, she would attend the meeting this afternoon.(fact:she is very busy, so she will not attend the meeting this afternoon.)
If they didn’t take physical exercises every day, they wouldn’t be so healthy.(fact: they take physical exercises every day, so they are very healthy.)
b. 表示與過去誓死相反的情況
①形式;
條件從句的動詞形式 主句的動詞形式
If I (we,you,he,she,it,they)+had+過去分詞 I (we) should
You (he,she , +have+過去分詞或:
they,it ) would
所有人稱+could(might)+have+過去分詞
②用法:
I would have checked my paper again if I had had more time at yesterday’s examination.(fact:I had no more time at yesterday’s exam, so I didn’t check my paper again)
You would have already recovered from his illness if he had seen the doctor in good time.(fact: He didn’t see the doctor in good time ,so he hasn’t recovered from his illness )
c. 表示與將來事實相反的情況
①形式:
條件從句的動詞形式 主句的動詞形式
a. If I (we,you,he,she,it,they)+行為動詞的過去式(be的過去式一般用were)通常要與一個表將來的時間的狀語連用
b. If (we,you,he,she,it,they)+should
+動詞原形
c. If I (we,you,he,she,it,they)+were to+動詞原形 I (we) should
You would +動詞原形或:
he(she,it ) would
they would
I (we,you,he,she,it,they)+could(might)+動詞原形
②用法:
If it rains tomorrow, our picnic will be put off.(The weather has been changeable these days.)
If it rained tomorrow, our picnic would be put off.( The weather has beenvery good these days.)
If it should rain tomorrow, our picnic would be put off.(That would be out of our expectation.)
If it were to rain tomorrow, our picnic would be put off. (條件從句謂語動詞用were to +動詞原形,表示 下雨的可能性極小。Were to rain和should rain 都表示“出乎意料之外”,但were to加強表示“當(dāng)初沒想到以后的事”)
c. 混合時間條件句的用法:
有時條件從句的動作和主句動作發(fā)生的 時間不一致。這時動詞的形式,應(yīng)根據(jù)它所要表達(dá)的具體時間來決定用什么形式。
1) If she hadn’t trained so hard, she wouldn’t be run so fast.(從句敘述過去,主句敘述現(xiàn)在。)
(fact: she has trained very hard, so she would able to run fast.)
2)You would speak English well enough if you had practised reading and speaking it every day.(主句敘述現(xiàn)在,從句敘述過去)
(fact: You didn’t practice (hasn’t practiced ) reading and speaking it every day, so you can’t speak English well enough.)
2、 在其他狀語從句中的用法
主要用于由as if (as though) 引導(dǎo)的比較狀語從句,從句中謂語動詞一般用“動詞的過去式(be 變were )或had +過去分詞。”
如:
She looked as if she were ill.(實際上她沒有病,在這里用虛擬語氣補語比喻她精神不佳)
Xiao Liu speaks English so well as if he had studied in England.(這里用虛擬語氣表現(xiàn)他的 英語說得好)

(2)、在主語從句中的用法:
通常由形式主語it引出的主語從句來表達(dá)。主語從句中,謂語動詞用“should+動詞原形”;表示“必要”“重要”“奇怪”等意思。
It is necessary that you should clean the workshop after work.下班后你必須清掃車間。
It is important that we should ask advice of other people about our work.在中,征求別人的意見是很重要的。

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