一.虛擬語氣

虛擬語氣表示說話人的主觀愿望、猜疑、建議或與事實不符的假設等，而不表示客觀存在的事實。虛擬語氣是由句中的謂語動詞的特殊形式表示出來的。

虛擬語氣主要分為與現在事實相反，與過去事實相反以及與將來事實相反三個種類。讓我們一一來看下它們的結構和用法吧!

1、表示與現在事實相反的情況

從句：If+主語+動詞一般過去時(Be動詞用were)

主句：主語+ should/would/might/could+do：

If I were you，I would take an umbrella.

如果我是你，我會帶把傘。(事實：我不可能是你)

If I knew his telephone number，I would tell you.

如果我知道他的電話號碼，我就會告訴你。(事實：不知道)

If there were no air or water，there would be no living things on the earth.

如果沒有水和空氣，地球上就不會有生物。(事實：地球上既有空氣也有水)

If I had any money with me，I could lend you some.

如果我帶錢了，我就會借給你些。(事實：沒有帶錢)

If he studied harder，he might pass the exam.

如果他再努力些，就能通過考試了。(事實：沒有努力)

If I were you， I’d wear a shirt and tie.

如果我是你，我就會穿襯衫和領帶。(事實：我并不是你)

2、表示與過去事實相反的情況

從句：If+主語+had+done

主句：主語+should/would/might/could+have done

eg：If I had got there earlier，I should/would have met her.

如果我早到那兒，我就會見到她。(事實：去晚了)

If he had taken my advice，he would not have made such a mistake.

如果他聽我的勸告的話，就不會犯這樣的錯誤了。

(事實：沒有聽我的話)

3、表示與將來事實相反

從句：①if+主語+were to do

②if+主語+should+do

③if+主語+動詞一般過去式(be動詞用were)

主句：主語+should/would/might/could+do

eg：If he should come here tomorrow，I would talk to him.

如果他明天來這兒的話，我就跟他談談。(事實：來的可能性很小，不可能)

If there were a heavy snow next Sunday，we would go skating.

如果下周日下大雪，我們就去滑冰。(事實：下雪可能性很小，不可能)

If she were to be here next Monday，I would tell her about the matter.

如果她下周一來這兒的話，我就會告訴她這件事的始末。(事實：來的可能性很小，不可能)