虛擬語(yǔ)氣分三種情況來(lái)掌握：
1、虛擬條件句。
2、名詞性虛擬語(yǔ)氣。
3、虛擬語(yǔ)氣的其他用語(yǔ)。
一、虛擬條件句：
條件狀語(yǔ)從句是非真實(shí)情況，在這種情況下要用虛擬語(yǔ)氣。
1、條件從句與現(xiàn)在事實(shí)不一致，其句型為：
If 主語(yǔ)＋過(guò)去時(shí)，主語(yǔ)＋should（could， would， 或might）＋動(dòng)詞原形，如：
If I were you， I would study hard.
If it rained， I would not be here now.
2、條件從句與過(guò)去事實(shí)不一致，句型為：
If 主語(yǔ)＋had＋過(guò)去分詞，主語(yǔ)＋should（could， would， 或might）＋have＋過(guò)去分詞，如：
If the doctor had come last night， the boy would have saved.
If I had not studied hard， I would have failed in the exam last term.
3、條件從句與將來(lái)事實(shí)不一致，句型為：
＋do，主語(yǔ)＋should（could…）＋ 原形 do
過(guò)去時(shí)（與現(xiàn)在事實(shí)條件句一樣）。
If it should rain tomorrow， we would stay at home.
If I were to go to the moon one day， I could see it with my own eyes.
If you missed the film to night， you would feel sorry