虛擬語(yǔ)氣考點(diǎn) 狀語(yǔ)從句常見(jiàn)引導(dǎo)詞

考點(diǎn)1 狀語(yǔ)從句常見(jiàn)引導(dǎo)詞

根據(jù)其作用可分為時(shí)間、地點(diǎn)、原因、條件、目的、結(jié)果、讓步、方式和比較等從句。常用引導(dǎo)詞如下表：

1. when的用法

（1）when表示時(shí)間點(diǎn)和時(shí)間段。有時(shí)相當(dāng)于as soon as/immediately/instantly/directly等詞的意思。when用于固定結(jié)構(gòu)“hardly/scarcely... when...”，此時(shí)when 可換作before。注意：當(dāng)把hardly/scarcely放句首時(shí)，句子需部分倒裝。

We will start when the monitor comes. 班長(zhǎng)一來(lái)，我們就出發(fā)。

I had hardly arrived home last night when it began to rain.=Hardly had I arrived home last night when it began to rain. 昨晚我一到家，就開(kāi)始下雨了。

（2）when 有時(shí)可譯為“如果……”，相當(dāng)于if，引導(dǎo)條件狀語(yǔ)從句。

Smog will be distant from us when everyone fights against pollution.

如果人人反對(duì)污染，霧霾就會(huì)遠(yuǎn)離我們。

（3）when可作并列連詞，引導(dǎo)并列分句，意為“突然……”或“這時(shí)……”，表示一個(gè)動(dòng)作“正在發(fā)生”“即將發(fā)生”“剛剛完成”時(shí)突然插入另一個(gè)動(dòng)作。when相當(dāng)于and just time或and just at that time,常用于下列三種句型：was/were doing... when...; was/were about to do（on the point of doing）... when...; had done... when...例如：

I was walking along the river when I heard a drowning boy crying for help.

我正沿著河邊走，突然聽(tīng)到一個(gè)溺水兒童的呼救。

I was about to go out when an unexpected visitor came.

我正要出門，一位不速之客來(lái)訪了。

We had just planted 100 trees when it began to rain.

我們剛剛栽完100棵樹(shù)，就開(kāi)始下雨了。

2. while的用法

while表示時(shí)間段，作并列連詞，表示前后對(duì)比。while引導(dǎo)的讓步狀語(yǔ)從句多放在句首，相當(dāng)于although，表示“盡管，雖然”。

There’s plenty of rain in the southeast, while there’s little in the northeast.

東南部雨量充足，而東北部則很少下雨。

While I understand what you say, I can’t agree with you.

雖然我理解你的意思，但我還是不能贊同你。

注意

① when引導(dǎo)的時(shí)間狀語(yǔ)從句既可放在句首，也可放在句末；而while引導(dǎo)的讓步狀語(yǔ)從句一般放在句首，不放在句末；另外，也可以從意義上加以區(qū)分。

② while和when都可以引導(dǎo)時(shí)間狀語(yǔ)從句，但應(yīng)注意：while引導(dǎo)的時(shí)間狀語(yǔ)從句中的謂語(yǔ)動(dòng)詞必須是延續(xù)性的動(dòng)詞；而when引導(dǎo)的時(shí)間狀語(yǔ)從句中的謂語(yǔ)動(dòng)詞既可以是延續(xù)性動(dòng)詞，也可以是非延續(xù)性動(dòng)詞。當(dāng)時(shí)間狀語(yǔ)從句中的謂語(yǔ)動(dòng)詞是延續(xù)性動(dòng)詞時(shí)，while和when 可以互相替換。例如：

The bus had left when we arrived at the bus stop. 當(dāng)我們到達(dá)車站時(shí)，公共汽車已經(jīng)開(kāi)走了。（arrive是非延續(xù)性動(dòng)詞，因此，此句中的when不能用while替換）

When/While we were having a meeting, our teacher came in. 我們正在開(kāi)會(huì)時(shí)，老師走了進(jìn)來(lái)。（have是延續(xù)性動(dòng)詞，因此，句中的when可以用while替換）

③ while引導(dǎo)的狀語(yǔ)從句還可以表示“某個(gè)動(dòng)作正在進(jìn)行的同時(shí)，另一個(gè)動(dòng)作也在進(jìn)行之中”。例如：

While the teacher was speaking, the students were listening. 老師在講課，學(xué)生們?cè)诼?tīng)。

3. as的用法

（1）as與when, while都是引導(dǎo)時(shí)間狀語(yǔ)從句的從屬連詞，含義都是“當(dāng)……的時(shí)候”。as意為at the same time that“正當(dāng)……；與……同時(shí)”，它兼指“時(shí)間點(diǎn)”和“時(shí)間段”，從句的動(dòng)詞既可是延續(xù)性動(dòng)詞，也可是非延續(xù)性動(dòng)詞，意為“一邊……一邊……”，“隨著”。

The door bell rang as we were having breakfast. 正當(dāng)我們吃早飯的時(shí)候，門鈴響了。

As the time went on（=With the time going on）, the weather got worse and worse.

隨著時(shí)間的推移，天氣越來(lái)越糟。

（2）while意為during the time that“在……期間”，指一個(gè)“時(shí)間段”，不能表達(dá)“時(shí)間點(diǎn)”，從句的動(dòng)詞只限于延續(xù)性動(dòng)詞；when意為at the time that“在……時(shí)”，多指“時(shí)間點(diǎn)”。

Strike while the iron is hot. 趁熱打鐵。

It was snowing when he arrived at the construction site. 他到達(dá)工地時(shí)正在下雪。

（3）as可以引導(dǎo)讓步狀語(yǔ)從句。as與although（或though），however（或no matter how）等都可以引導(dǎo)讓步狀語(yǔ)從句，含義是“雖然，盡管”，但它們有區(qū)別：although語(yǔ)氣稍正式些，可放在句首，也可放在句中，主句中不能再用but，但可以用yet；as所表達(dá)的語(yǔ)氣較強(qiáng)，引導(dǎo)的讓步狀語(yǔ)從句用倒裝語(yǔ)序；however引導(dǎo)讓步狀語(yǔ)從句時(shí)，它的后面可跟形容詞或副詞，也要用倒裝語(yǔ)序。

Strange as it may seem, nobody was injured in the accident.

這次意外雖然很奇怪，卻沒(méi)有人受傷。

Young as he is, he knows everything. 盡管小，他什么都知道。

還可表達(dá)為：

Though he is young, he knows everything.

Young though he is, he knows everything.

Although he is young, he knows everything.

However young he is, he knows everything.

另外，though還可以作為副詞，意為“可是，然而，不過(guò)；話雖這樣說(shuō)”，一般位于句尾。

I wish you had told me, though. 不過(guò)，我希望你曾告訴過(guò)我。

He said he would come, he didn’t, though. 他說(shuō)他要來(lái)，可是他并沒(méi)有來(lái)。

另外，as還可以引導(dǎo)原因狀語(yǔ)從句。

As rain has fallen, the air is cooler. 因?yàn)橄逻^(guò)雨，空氣比較清爽。

4. so/such... that... 均可引導(dǎo)結(jié)果狀語(yǔ)從句

該句型中的such是形容詞，修飾名詞；so是副詞，修飾形容詞或副詞，具體的搭配形式是：“so+adj./adv.+that”，“so+adj.（+a/an）+n.+that”；“such（+a/an）（+adj.）+n.+that”。

He speaks so fast that no one can catch him. 他說(shuō)話太快，無(wú)人聽(tīng)得明白。

He’s such a good person that we mustn’t blame him.

他是這么好的人，我們千萬(wàn)不要怪他。

There is so rapid an increase（=such a rapid increase）in population that a food shortage is caused. 人口增長(zhǎng)如此迅速，以致造成了糧食短缺。

They are such fine teachers that we all hold them in great respect.

他們是非常好的老師，我們對(duì)他們極為尊敬。

It is such nice weather that I would like to go to the beach. 天氣如此好，我想去海灘。

The country has so much coal that it can export large quantities. 那個(gè)國(guó)家的煤炭非常豐富，可以大量出口。（so與表示數(shù)量的代詞many, few, much, little等連用已經(jīng)形成固定搭配，不能換用such）

5. It be... since/before/when... 從句歸納

6. 其他連詞（或副詞、名詞）

· after 在……之后

· before 在……之前

· since 自從……（引導(dǎo)時(shí)間狀語(yǔ)從句，主句需使用完成時(shí)態(tài)）

· once 一旦……（也可用作副詞，意為“曾經(jīng)，一度”）

· whenever 無(wú)論何時(shí)，每當(dāng)……

· immediately/directly 一……就……（相當(dāng)于as soon as，個(gè)別語(yǔ)法學(xué)家已經(jīng)賦予這類副詞連詞詞性）

· the moment/minute 每當(dāng)……；一……就……（相當(dāng)于as soon as）

· each/every time 每當(dāng)……

例如：

Where have you been since I last saw you? 自從我上次見(jiàn)到你以后，你到哪兒去了？

Once you understand this rule, you’ll have no further difficulty.

一旦你明白了這條規(guī)則，就再也沒(méi)有困難了。

Whenever I hear that song, it makes me think of you.

每當(dāng)我聽(tīng)到那首歌，我就會(huì)想起你。

I came immediately/directly I got your message. 一收到你的消息，我就來(lái)了。

He said he’d phone you the moment he got home. 他說(shuō)他一到家就會(huì)給你打電話。

I meet up with Julie every time I go to Washington.

每次我去華盛頓的時(shí)候，我都會(huì)見(jiàn)朱莉。