is
引導條件狀語從句最常用的連詞是if,由if引導的條件狀語從句表示在某種條件下某事很可能發(fā)生.如:
If you ask him,he will help you.如果你請他幫忙,他會幫你的.
If you fail in the exam,you will let him down.如果你考試不及格,你會讓他失望的.
另外,if從句還表示不可實現(xiàn)的條件或根本不可能存在的條件,也就是一種虛擬的條件或假設,從句多用一般過去時或過去完成時.如:
If I were you,I would invite him to the party.如果我是你,我會邀請他參加聚會.
I would have arrived much earlier if I had not been caught in the traffic.如果沒有堵車,我會到的早一點兒.