條件狀語從句分為真實條件和非真實條件兩種.前者表示真實的或可能變成現(xiàn)實的條件，后者表示非真實的或不可能變?yōu)楝F(xiàn)實的條件.真實條件句要用一般時標(biāo)將來。

　　例：Oil floats if you pour it on water.

　　The sports meet will be put off if it rains tomorrow.

　　If I were you, I would refuse the money.

　　虛擬式的基本形式 (后面我們再詳細講虛擬語氣)

　　If we left now, we should arrive in time.

　　If we had left time, we would have dropped by.

　　If you dropped the glass, it would break.

　　The tennis finals will be put off if it ______ tomorrow afternoon. (2005/4)

　　A. rains B. will rain

　　C. were to rain D. was to rain

　　A

　　讓步狀語從句，關(guān)聯(lián)詞：though, although, if, even if, even though, in spite of the fact that等.

　　例：

　　1. Though it was only nine o’clock, there were few people in the street.

　　2.He went out in spite of the fact that he had a bad cold.

　　Exercises

　　1. If you smoke in a non-smoking section people _____.

　　A) have objected B) objected

　　C) must objected D) will object

　　2. A man escaped from the prison last night. It was a long time _____ the guards discovered what had happened.

　　A) before B) until C) since D) when

　　3. Government cannot operate effectively _____ it is free from such interference.

　　A) so long as B) so that

　　C) unless D) because

　　D C C

　　4. Not that John doesn't want to help you, _____it's beyond his power.

　　A) but that B) for that

　　C) and that D) in that

　　5. Man differ from animals ____ they can think and speak.

　　A) in that B) for that

　　C) with that D) at that