首頁 »
2009/02/08

【英語教室】23. 假設法 - 與事實相反的假設

【假設法】(Conditional Sentences) 算是學英文的過程中,會遇到的重要瓶項之一,但如果能夠靜下來,好好研究一下其中規則,搞懂之後,就可以天下無敵了啦!

前一單元《有可能的假設》,講解現在或未來有可能發生的情況,比如:「明天下雨的話,我就不出門。」如果那一章節還不了解,最好再回頭看一下,至少要十個習題都完全答對了,再來進行這一章節。

否則,看到頭昏腦脹、眼冒金星,本人概不負責。

與事實相反的假設,可以分為兩種:

‧與現在事實相反,比如:如果狗是鳥,就會飛。 (狗不可能變成鳥,所以不會飛)
‧與過去事實相反,比如:如果他早起,就不會遲到了。 (因為他晚起,所以遲到了)
 又或者,與過去事實相反的假設,造成了與現在事實不相符的結果,
 比如:他當年如果用功讀書,現在就是醫生了。 (他以前不用功,所以現在不是醫生)

先搞懂了以上三種邏輯性,再往下看英文怎麼用。

【記法】動詞與應該使用的時態不同,而我的記法很簡單,就是所有的動詞,都往後退一格。也就是,以原本《有可能發生的假設》為基型,If 的子句和主要子句,各隨著對應時態退後一格:

 未來有可能發生:If + 主詞 + 現在式, 主詞 + will / may / can + 原形  
 與現在事實相反:If + 主詞 + 過去式, 主詞 + would / might / could + 原形 
 與過去事實相反:If + 主詞 + 過去完成式(had p.p.), 主詞 + would/might/could + 完成式(have p.p.) 


‧與現在事實相反
 If + 主詞 + 過去式 (Be 動詞用 were), 主詞 + would/might/could + 原形動詞

【注意】不論主詞為何,如果要用 Be 動詞時,一律使用 were,不用 was.

 例一:如果狗是鳥,就會飛。 (狗永遠不會變成鳥)
    If dogs were birds, they could fly.

 例二:如果我是你,就會買那輛車。 (我永遠不會變成你)
    If I were you, I would buy that car.

 例三:如果我們有錢,就能請律師。 (我們現在沒有錢,請不起律師)
    If we had money, we could hire a lawyer.


‧與過去事實相反 
 If + 主詞 + had + 過去分詞(p.p.), 主詞 + would/might/could + have + 過去分詞(p.p.)


 例一:如果他早起,就不會遲到了。
    If he had got up early, he would not have been late.

 例二:如果昨天沒下雨,我們就可以打棒球了。
    If it had not rained yesterday, we could have played baseball.

 例三:如果我早上坐公車,就會遇到他了。
    If I had taken the bus this morning, I would have met him.


‧前兩者的綜合,也就是與過去相反的假設,造成了現在不同的結果。動詞變化方面,只要記得,看句子的意思是與現在不同還是過去不同,「往後退一格」,就行了。

 例一:他當年如果用功讀書,現在就是醫生了。 (過去不用功,現在不是醫生)
    If he had studied hard, he would be a doctor.

 例二:如果你昨晚打電話給我,現在就跟我們在一起了。
    If you had called me last night, you would be with us now.

 例三:如果當時我買了那電腦,現在就要後悔了。
    If I had bought that computer, I would be regretful.

※If 領導的子句可放在後面,與主要子句之間不加逗號。(詳情請見前一單元最後一項)

 例一:If he had studied hard, he would be a doctor.
    He would be a doctor if he had studied hard.

 例二:If we had money, we could hire a lawyer.
    We could hire a lawyer if we had money.


【練習】請填入適當的動詞形態 (注意:混合了前一單元)

1. If you _______ (eat) the fish yesterday, you would be sick.
2. If the teacher spoke louder, the students _______ (understand) better. 
3. If we meet at 10:30, we _______ (have) plenty of time.
4. The little girl would find candy if she _______ (check) the fridge. 
5. If I _______ (be) you, I _______ (call) her.
6. The door will open if you _______ (hit) the button. 
7. You _______ (feel) cold if you _______ (swim) in winter.
8. If she invited me, I _______ (accept).
9. He _______ (write) a good report if he had learned more words.
10. If you _______ (join) the club, you would have met lots of people.


【解答】

1. had eaten
2. would understand
3. will have
4. checked
5. were / would call
6. hit
7. will feel / swim
8. would accept
9. could have written
10. had joined

關鍵字: 研究

【英語教室】22. 假設法 - 有可能的假設←上一篇 │首頁│ 下一篇→【英語教室】24. 倒裝句
本文引用網址: