先來看兩個句子:
1 I will go out tomorrow if it is fine.
2 I don"t know if the train has arrived.
句 1 中if引導的是狀語從句。這個從句表示“條件”,修飾主句。整個句子的意思是“如果明天天氣好,我們就出去。”句 2 中if引導的是賓語從句,充當謂語動詞don"t know的賓語。整個句子的意思是“我不知道火車是否到了。”
虛擬語氣在條件狀語從句中的用法
1. 表示與現在事實相反的情況,其句型為“ if+ 主語 + 動詞的過去式( be 動詞用 were ),主語 +would / could / might / should + 動詞原形”。如:
If the weather were fine, we would go to Shanghai.
如果天氣好,我們就去上海。(事實上天氣不好)
If they had time, they would / could / might go with me.
如果他們有時間,他們就會(可能)和我一起去。
2. 表示與過去事實相反的情況。其句型為“ if + 主語 + 動詞的過去完成式,主語 +would / could / should / might + have + 動詞的過去分詞”。如:
If I had taken his advice, I shouldn"t / wouldn"t / couldn"t have made such a mistake.
如果我按照他的建議去做,我一定不會(不可能)犯這樣的錯誤。
3. 表示與將來事實可能相反的假設和結果,其句型為“ if + 主語 + 動詞的過去式 / should + 動詞原形 / were to + 動詞原形,主語 +would / could / might / should + 動詞原形”。如:
The glass would break if you dropped it.
杯子摔下來會打破的。(事實上沒有摔下來)
If it should rain, the crops would / could / might be saved.
假如天下雨,莊稼就一定(有可能)會得救。
注意:主句中的 should 只用於第一人稱,但在美國英語中, should 常被 would 代替;從句中的 should 可用於各種人稱。
先來看兩個句子:
1 I will go out tomorrow if it is fine.
2 I don"t know if the train has arrived.
句 1 中if引導的是狀語從句。這個從句表示“條件”,修飾主句。整個句子的意思是“如果明天天氣好,我們就出去。”句 2 中if引導的是賓語從句,充當謂語動詞don"t know的賓語。整個句子的意思是“我不知道火車是否到了。”
虛擬語氣在條件狀語從句中的用法
1. 表示與現在事實相反的情況,其句型為“ if+ 主語 + 動詞的過去式( be 動詞用 were ),主語 +would / could / might / should + 動詞原形”。如:
If the weather were fine, we would go to Shanghai.
如果天氣好,我們就去上海。(事實上天氣不好)
If they had time, they would / could / might go with me.
如果他們有時間,他們就會(可能)和我一起去。
2. 表示與過去事實相反的情況。其句型為“ if + 主語 + 動詞的過去完成式,主語 +would / could / should / might + have + 動詞的過去分詞”。如:
If I had taken his advice, I shouldn"t / wouldn"t / couldn"t have made such a mistake.
如果我按照他的建議去做,我一定不會(不可能)犯這樣的錯誤。
3. 表示與將來事實可能相反的假設和結果,其句型為“ if + 主語 + 動詞的過去式 / should + 動詞原形 / were to + 動詞原形,主語 +would / could / might / should + 動詞原形”。如:
The glass would break if you dropped it.
杯子摔下來會打破的。(事實上沒有摔下來)
If it should rain, the crops would / could / might be saved.
假如天下雨,莊稼就一定(有可能)會得救。
注意:主句中的 should 只用於第一人稱,但在美國英語中, should 常被 would 代替;從句中的 should 可用於各種人稱。