、 條件句中的虛擬語氣
1.條件句中虛擬語氣的形式
從句中提出一種與客觀現(xiàn)實不相符或根本不可能存在的條件,主句會產(chǎn)生的一種不可能獲得的結果.條件句中的虛擬語氣根據(jù)不同的時間有三種不同的形式.
時間
從句謂語形式
主句謂語形式
將來
動詞過去式(be用were)
should + 動詞原形
were to + 動詞原形
would / should / might / could + 動詞原形
現(xiàn)在
動詞過去式(be 用 were)
would / should / might / could + 動詞原形
過去
had +動詞過去分詞
would / should / might / could have + 動詞過去分詞
2.條件句中的虛擬語氣的舉例
(1) 將來時的條件句中的虛擬語氣.如：
If he should go to Qing Hua University,he would make full use of his time.如果他要上清華大學的話,他就會充分利用他的時間了.
If he were to come here,he would tell us about it.如果他要來的話,他會通知我們一聲.
(2) 現(xiàn)在時的條件句中的虛擬語氣.如：
If he were free,he would help us.要是他有空的話,它會幫助我們的.
If he studied at this school,he would know you well.如果他在這所學校學習的話,它會對你很熟悉.
(3) 過去時的條件句中的虛擬語氣.如：
If I had seen the film,I would have told you about it.我如果看過這場電影,我會把電影內容告訴你了.
If I had got there earlier,I would have met Mr.Li.如果我早點到那兒,我就會會到了李先生.
3.運用條件句中的虛擬語氣時,須注意的幾個問題
(1) 當從句的主語為第三人稱單數(shù)時,謂語動詞若是系動詞be時,可用 was 代替 were.但在倒裝虛擬結構及 if I were you,as it were 中,只能用 were.如：
Were I ten years younger,I would study abroad.要是我還年輕十歲的話,我會去國外學習.
If I were you,I would try my best to grasp the chance.要是我是你的話,我要盡力抓住這次機會.
(2) 有時,虛擬條件句中,主、從句的動作若不是同時發(fā)生時,須區(qū)別對待.
①從句的動作與過去事實相反,而主句的動作與現(xiàn)在或現(xiàn)在正在發(fā)生的事實不符.如：
If I had worked hard at school,I would be an engineer,too.如果我在學校學習刻苦的話,我現(xiàn)在也會使工程師了
If they had informed us,we would not come here now.如果他們通知過我們的話,我們現(xiàn)在就不會來這里了.
②從句的動作與現(xiàn)在事實相反,而主句的動作與過去事實不符.如：
If he were free today,we would have sent him to Beijing.如果他今天有空的話,我們會已經(jīng)派他去北京了.
If he knew her,he would have greeted her.要是他認識她的話,他肯定會去問候她了.
③從句的動作與過去發(fā)生的情況相反,而主句的動作與現(xiàn)在正在發(fā)生的情況相反.如：
If it had not been raining too much,the crops would be growing much better.如果天不下太多的雨的話,莊家會長得更好.
If he had been working hard,he would be working in the office now.要是他工作一直努力的話,他現(xiàn)在已進了辦公室了.
(3) 當虛擬條件句的謂語動詞含有 were,should,had 時,if 可省略,而將 were,should,had等詞置于句首.如：
Should he agree to go there,we would send him there.要是他答應去的話,我們就派他去.
Were she here,she would agree with us.如果她在這兒的話,她會同意我們的.