虛擬語氣：
1、中文：我要是你，我不會那么做。
（誤）I shouldn't do that if I was you.
（正）I shouldn't do that if I were you.（表示與現(xiàn)在事實相反的虛擬語氣不能用was，只能用were.）
 
2、中文：要是我父親現(xiàn)在在這里，他會告訴我該做什么。
（誤）If my father were here now，he will tell me what to do.
（正）If my father were here now，he would tell me what to do.（表示與現(xiàn)在事實相反的虛擬語氣中，主句的助動詞只能用would，might等過去時。）
 
3、中文：要是我知道她的電話號碼，我就會給她打電話了。
（誤）If I knew her telephone number，I would have called her.
（正）If I had known her telephone number，I would have called her.（表示與過去事實相反的虛擬語氣中，條件從句的動詞要用過去完成時。）
 
4、中文：要是昨天沒下雨她也許會來。
（誤）If it had not rained yesterday，he might come.
（正）If it had not rained yesterday，he might have come.（表示與過去事實相反的虛擬語氣中，主句的動詞要用助動詞的過去時might，could等+HAVE+過去分詞。）
 
5、中文：我不認為我會失敗，但要是我失敗了，我會再努力。
（誤）I don't think that I shall fail. But if I failed，I would try again.
（正）I don't think that I shall fail. But if I should fail，I would try again.（表示與將來事實相反的虛擬語氣中，條件從句的動詞用should加原形動詞。）
 
6、中文：他要是帶了錢就會買它。
（誤）Did he bring some money with him，he would have bought it.
（正）Had he brought some money with him，he would have bought it.（表示與過去事實相反的虛擬語氣中，條件從句的動詞要用過去完成時，若省略if，則用倒裝形式。）
 
7、中文：她要是個男人可能會當選總統(tǒng)。
（誤）Be she a man，she might be elected president.
（正）Were she a man，she might be elected president.（表示與現(xiàn)在事實相反的虛擬語氣，不能用was，只能用were；若省略if，則將were放在句首。）
 
8、中文：我提議提高教師的薪資。
（誤）I suggested that the teachers' wages could be increased.
（正）I suggested that the teachers' wages should be increased.（suggest當建議講時，后面的名詞從句的主要動詞要用should加原形動詞，should可以省略。）
 
9、中文：他這么做是重要的。
（誤）It is important that he will do it.
（正）It is important that he do it.（It is important+that引導的名詞從句的動詞要用should加原形動詞，should可以省略。）