虛擬條件句的基本類型與結(jié)構(gòu)

一、與現(xiàn)在事實(shí)相反

若與現(xiàn)在事實(shí)相反，虛擬語(yǔ)氣的條件從句的謂語(yǔ)用過去式(be通常用were)，主句謂語(yǔ)用“should (would, could, might)+動(dòng)詞原形”。如：

If you took a taxi，you'd get there quicker. 如果你坐出租車去，你可以快一點(diǎn)到那里。(但你不坐)

If I knew her number I could ring her up. 要是我知道她的電話號(hào)碼，我就可以給她打電話了。(可惜我不知道)

二、與過去事實(shí)相反

若與過去事實(shí)相反，虛擬語(yǔ)氣的條件從句的謂語(yǔ)用過去完成時(shí)(had+過去分詞)，主句謂語(yǔ)用“should (would, could, might)+have+過去分詞”。如：

If I'd left sooner，I'd have been on time. 要是我早點(diǎn)動(dòng)身，我就準(zhǔn)時(shí)到了。(但我動(dòng)身太遲了)

If we had found him earlier we could have saved his life. 要是我們當(dāng)時(shí)早點(diǎn)找到他的話，我們就可以救活他。(可惜我們找到他太晚了)

三、與將來事實(shí)相反

若與將來事實(shí)相反，條件從句的謂語(yǔ)用過去式(be通常用were)，主句謂語(yǔ)用“should (would, could, might)+動(dòng)詞原形”。如：

If he went，would you go too? 如果他去，你也去嗎?(大概他不會(huì)去)

If I asked him，I'm sure he'd help us. 如果我向他提出要求，肯定他會(huì)幫助我們。(不過我不打算這樣做)

注意與說明：對(duì)于與將來事實(shí)相反的情形，請(qǐng)注意以下幾點(diǎn)：

一是這里說的與將來事實(shí)相反，實(shí)為對(duì)將來情況的推測(cè)；

二是此用法中的條件從句謂語(yǔ)除用過去式外，有時(shí)也用“should+動(dòng)詞原形”(表示可能性極小，常譯為“萬(wàn)一”)或“were to+動(dòng)詞原形”(表示與將來事實(shí)相反的假設(shè))；

三是當(dāng)條件從句使用“should+動(dòng)詞原形”這樣的謂語(yǔ)時(shí)，主句謂語(yǔ)除可用“should (would, could, might)+動(dòng)詞原形”這樣的虛擬語(yǔ)氣外，也可用陳述語(yǔ)氣或祈使語(yǔ)氣。如：

If I should see him, I'll tell him. 萬(wàn)一我見到他，我就告訴他。

If it should rain tomorrow, don’t expect me. 萬(wàn)一明天下雨，就別等我了。