虛擬語氣表示說話人的主觀愿望,、猜疑,、建議或與事實(shí)不符的假設(shè)等，而不表示客觀存在的事實(shí),。

Beyoncé 的歌詞中 'If I were a boy'.如果我是個男孩,，就是這樣一個句型。

先來感受下這些表達(dá)吧：

1.I wouldn’t wear a sweater in such hot weather if I were you.

換做我是你,，我不會在這樣的大熱天穿毛衣,。

2.If I were you,I would explain to Jack what happened.

如果我是你，我會想杰克解釋事情的經(jīng)過,。

3.If I were you, I should get another lawyer. 

如果我是你,，我就請別的律師,。

4.I would think about it very carefully, if I were you. 

我要是你的話，我就十分慎重地考慮這件事,。

一.常用句型及表達(dá)：

在虛擬語氣中我們通常用：If I were...,I would...句型

Eg：1.If I were you, I would study harder. 

2.If I were you, I would stop doing that.

3.If I were you, I would go to the doctor.

你還可以更改句子順序,，這種語序就沒有必要用逗號了，變成：

1.I would study harder if I were you.

2.I would be more careful if I were you.

3.I wouldn't do that if I were you.

二.在虛擬語氣中我們還可以用其他人稱做主語：

IF + I / HE / SHE / IT + WERE

Eg：1.If I were you, I wouldn't play with fire.

（第一人稱）

2.If you were me,would you study English or go to the movie?

如果你是我,，你會學(xué)英語還是去看電影,。（第二人稱）

3.If he were taller, he'd be accepted into the team.

要是他再高點(diǎn)，我就同意他加入小組了,。（第三人稱）

*三.在虛擬語氣中,，如果要表示“我要是你”，通常是用 If I were you 的,，但可以用 If was you 嗎,？

首先if I was這個句子語法上沒錯,，但并不是虛擬語氣了,，而是陳述語氣;

Eg：1.If I was sick, she would give me medicine that tasted terrible. 

如果我生病了，他就會給我吃很難吃的藥,。

2.If I were sick, I wouldn't be here. 

如果我生病了,，我就不會在這。（言外之意我沒有生病,，我是給出了假設(shè)的情況）

這是一個語法學(xué)家們有分歧的問題：

有的語法學(xué)家認(rèn)為 If I were you 不能說成 If I was you,。比如《朗文英語語法》在14.13.2節(jié)就認(rèn)為在 If I were you / If I were in your position 中不用 was。該書所給例句為：

Eg：If I were you / in your position, I’d accept their offer. 

如果我是你,，我就接受他們的建議,。

但事實(shí)上，日常日?？陬^表達(dá)中也有些英語母語者會用“If I was”.

語言總是隨著人類表達(dá)習(xí)慣不斷改變,。沒有永恒不變的表達(dá)習(xí)慣。

建議：如果是初學(xué)者或作為學(xué)生參加考試,，以用 If I were you 為宜,。

四.總結(jié)用法：

虛擬語氣用在與現(xiàn)在事實(shí)相反條件句中時，條件從句的謂語用動詞的過去式 （be的過去式用were）,，結(jié)果主句的謂語用should(第一人稱)或would(第二,、三人稱)＋動詞原形。if 表示“如果”,，I “我”,，were是'are'的過去式，you”你”,，would在這里是'will '的過去式,，這里的過去式表示的都是假設(shè),，不可能發(fā)生的事情。

Eg：1.If I were stronger,I would train for the marathon.

如果我再強(qiáng)壯點(diǎn),，我就訓(xùn)練參加馬拉松,。

2.If I were an animal,I would be a lion.

如果我是動物，我就成為獅子,。

3.If I I were in charge,I would give everyone a vacation.

如果我管事兒,，我給所有人放假。

4.If I were you,I would not buy that dress.

如果我是你,，我不會買那條裙子,。

5.If I were you,I would study English and find a new job.

如果我是你，我會好好學(xué)習(xí)英語再找個新工作,。

6.I'd think twice before buying that car if I were you. 

如果我是你的話,，在買那輛車之前我會再三考慮的。