五、 連詞
(一) 知識(shí)概要
連詞是一種在句子與句子之間，短語(yǔ)之間以及名詞等其他詞語(yǔ)之間起連接作用的虛詞，它不能單獨(dú)作句子的成份。按其意義可分為并列連詞和從屬連詞兩大類。 并 列連詞連接的雙方是對(duì)等的。常有的并列連詞有and, both…and, either…or, neither…nor, not only…but also, as well as等。但如果連接的兩部分意義不趨向一致，意義有轉(zhuǎn)折的并列連詞有：but, however, while (而)，only (只不過(guò))。還有表示選擇關(guān)系的并列連詞，如：or, or else, otherwise… 再有的是連接雙方，互為因果，或表示前因后果的連詞有：for, so, therefore (因此)，then等。 從屬連詞在初中范圍內(nèi)常常用來(lái)連接名詞性從句，如：that, if, whether, 其次用來(lái)連接狀語(yǔ)從句。其中有原因狀語(yǔ)從句，常用的連接詞有：when while, as, since, before, after, once, as soon as, until, till 連接條件狀語(yǔ)的連詞有：if, unless, as long as 等，而原因狀語(yǔ)的連接詞有because, since, as, now that (既然)。目的、結(jié)果、方式、比較、地點(diǎn)等狀語(yǔ)從句的連接詞有：so that, so…that, such…that, as…as, than, where… 它們?cè)诰渥优c文章中幾乎無(wú)處不見(jiàn)。 具體用法見(jiàn)下表。
連詞用法一覽表
種類 功用 例句
并列連詞 連接具有并列關(guān)系的 詞 He knows neither English nor French.
短語(yǔ) Are you going by bus or on foot?
分句 Mary was a good girl, but she had one shortcoming.
從屬連詞 引導(dǎo)： 狀語(yǔ)從句 I'll do it as you told me.
You will be late unless you hurry.
連接代詞和連接副詞 主語(yǔ)從句 What he said proved true.
When we'll start has not been decided yet.
表語(yǔ)從句 This is why he didn't come yesterday.
That is where he lives.
賓語(yǔ)從句 The man asked me which I liked best.
I can't understand why she is so late.
關(guān)系代詞和關(guān)系副詞 定語(yǔ)從句 Nicotine is a drug that gets one into the habit of smoking.
He came last night when I was out.
(二) 正誤辨析
[誤] Both my parents are not here. They went to the concert just now.
[正] Neither of my parents is here. They went to the concert just now.
[析] 在英語(yǔ)中both一般用于肯定句中，如用于否定句中，其意義也不同于漢語(yǔ)，如：Both of us are not right. 在英語(yǔ)中應(yīng)被理解為"我們倆不都對(duì)。"而Neither of us is right. 才能被理解為"我們倆無(wú)一正確".
[誤] He or his parents has some tickets for the film.
[正] He or his parents have some tickets for the film.
[析] 由or 連接兩主語(yǔ)時(shí)，謂語(yǔ)動(dòng)詞應(yīng)與相臨近的那一個(gè)主語(yǔ)保持一致。
[誤] You should study hard, and you won't pass the exam.
[正] You should study hard, or you won't pass the exam.
[析] or作為連詞，這里的意思為"否則".又如：Hurry up, or you'll be late for school.
[誤] Though he is poor, but he is ready to help others.
[正] Though he is poor, he is ready to help others.
[正] He is poor, but he is ready to help others.
[析] "雖然……但是"是中文中的常用結(jié)構(gòu)，但在英文中用了"雖然"則不要用"但是",用了"但是"則不能再用"雖然",二者只可用其一。
[誤] Either you or I are on duty.
[正] Either you or I am on duty.
[析] either…or 連接兩個(gè)主語(yǔ)時(shí)，其謂語(yǔ)動(dòng)詞與相臨近的一個(gè)主語(yǔ)相呼應(yīng)，這也叫作就近原則。類似的用法還有or, neither… nor, not only…but also等。
[誤] Tom is our English teacher and teaching English in our school now.
[正] Tom is our English teacher and is teaching English in our school now.
[析] 并列句中常常在后面的句子中作一些省略，以免重復(fù)，但不是所有詞都可作任意的省略的。當(dāng)你連接的是兩個(gè)系動(dòng)詞時(shí)，后面的那個(gè)系動(dòng)詞不可省略，也就是講連接的部分不可省略。
[誤] My father likes swimming and to collect stamps.
[正] My father likes swimming and collecting stamps.
[析] 由并列連詞連接的兩個(gè)部分要保持相等的語(yǔ)法結(jié)構(gòu)。如是動(dòng)名詞則都用動(dòng)名詞，如用不定式則都應(yīng)用不定式，這是初學(xué)者要注意的一點(diǎn)。
[誤] My father is reading a newspaper, I am doing my homework.
[正] My father is reading a newspaper while I am doing my homework.
[析] 兩個(gè)并列句中間不可用逗號(hào)連接，要用并列連詞來(lái)連接。
[誤] My father asked me that if I wanted to learn how to drive.
[正] My father asked me if I wanted to learn how to drive.
[析] 賓語(yǔ)從句的連接詞只能有一個(gè)不能重復(fù)使用。
[誤] We will go both to Beijing and Shanghai.
[正] We will go to both Beijing and Shanghai.
[析] 用both…and…作連接詞時(shí)，其相連接的部分結(jié)構(gòu)也要相同。
[誤] Not only Mary but also her brothers is going to dance.
[正] Not only Mary but also her brothers are going to dance.
[析] 由not only… but also…連接兩個(gè)主語(yǔ)時(shí)，其重點(diǎn)在其后面的那一個(gè)主語(yǔ)，所以謂語(yǔ)形式應(yīng)采用就近原則。
[誤] The teacher as well as his students are coming.
[正] The teacher as well as his students is coming.
[析] 由as well as 連接兩個(gè)主語(yǔ)時(shí)，謂語(yǔ)動(dòng)詞與as well as 后面的名詞無(wú)關(guān)，而與前面的名詞相一致。
[誤] Tom does not swim nor play football.
[正] Tom does not swim or play football.
[析] nor主要用于連接句子的對(duì)等連詞，如在否定句中連接某一部分時(shí)要用or, 但要注意句子的含意，如：This animal does not like a cow or a horse. 這個(gè)動(dòng)物既不像牛也不像馬。This animal does not like a cow but a horse. 這個(gè)動(dòng)物不像牛而像馬。
[誤] For there is no light in the classroom. The students must have gone home.
[正] The students must have gone home, for there is no light in the classroom.
[析] 由for引出的原因狀語(yǔ)從句在使用時(shí)要注意不能將該從句置于句 首，而應(yīng)置于主句之后，并在主句與從句之間加一逗號(hào)。更要注意的是because, as, since與for 4個(gè)表示原因的連詞中because是因果關(guān)系，是最強(qiáng)的一個(gè)，而for是最弱的一個(gè)。有些語(yǔ)法書中干脆把for叫做并列連詞
[誤] My brother will pass the English exam is no question.
[正] That my brother will pass the English exam is no question.
[析] 主語(yǔ)從句的引導(dǎo)詞that是不可省略的。這一點(diǎn)不要和賓語(yǔ)從句的引導(dǎo)詞相提并論。
[誤] This map will show you how will you get to the hotel.
[正] This map will show you how you will get to the hotel.
[析] 名詞性從句作賓語(yǔ)從句使用時(shí)，最重要的一點(diǎn)是要用陳述語(yǔ)句。特別要注意的是那些使用雙賓語(yǔ)的動(dòng)詞，如：tell, ask, show…
[誤] While the clock struch ten, all the lights went out.
[正] When the clock struck ten, all the lights went out.
[析] while是強(qiáng)調(diào)兩個(gè)動(dòng)作在同時(shí)進(jìn)行中，如：While I am doing myhomework, my father is reading a newspaper. 而這里的when是"正當(dāng)某某時(shí)刻","就在這一時(shí)間點(diǎn)上",其重點(diǎn)強(qiáng)調(diào)在某一特定時(shí)刻某動(dòng)作的發(fā)生。
[誤] While I was walking along the street yesterday, I met an old friend.
[正] When I was walking along the street yesterday, I met an old friend.
[析] 這里用when表達(dá)在一個(gè)動(dòng)作的進(jìn)行中，另一個(gè)動(dòng)作突然發(fā)生了。正在進(jìn)行的動(dòng)作用一進(jìn)行時(shí)態(tài)，而突然發(fā)生的動(dòng)作用一般時(shí)態(tài)。
[誤] While I heard the bad news I felt sad.
[正] When I heard the bad news, I felt sad.
[析] while不能表達(dá)一點(diǎn)兒的時(shí)間，即瞬時(shí)某一時(shí)間點(diǎn)。
[誤] After school some students play football, or others go to the library.
[正] After school some students play football, while others go to the library.
[析] while在此處意為"而，然而".
[誤] She sang when she walked along the dark street.
[正] She sang as she walked along the dark street.
[析] as用于句中時(shí)，其要點(diǎn)是強(qiáng)調(diào)兩個(gè)動(dòng)作的同時(shí)進(jìn)行。這里用when雖然不能講是語(yǔ)法上的錯(cuò)誤，但則看不出來(lái)小女孩因獨(dú)自走黑暗的街道因害怕而唱歌的心情。
[誤] I finished my homework until twelve o'clock last night.
[正] I didn't finished my homework until twelve o'clock last night.
[正] I did my homework until twelve o'clock last night.
[析] until用在句中時(shí)其含義是某一動(dòng)作一直持續(xù)到某時(shí)結(jié)束，那么句中的動(dòng)詞則一定要用持續(xù)性動(dòng)詞，如果要用瞬間，或截止性動(dòng)詞時(shí)一定要用否定句式。因截止 性動(dòng)作的否定式應(yīng)看作是持續(xù)性的動(dòng)作。如離開(kāi)leave是瞬間動(dòng)作，因一出門即為離開(kāi)了，而不離開(kāi)則是長(zhǎng)時(shí)間的。
[誤] I have studied English when I was twelve.
[正] I have studied English since I was twelve.
[析] since引出的時(shí)間狀語(yǔ)從句是表達(dá)了一個(gè)時(shí)間點(diǎn)，而這個(gè)時(shí)間點(diǎn)是主句動(dòng)作的啟始點(diǎn)，所以主句一般要用完成時(shí)態(tài)。
[誤] Because he didn't study hard, so he didn't pass the exam.
[正] He didn't pass the exam because he didn't study hard.
[析] because 與 so在英文中兩者不能并用的，只能在句中用其一。
[誤] He was such excited that he could not speak.