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在英语学习中,好多同学对如何使用whether和if 感到模糊,常常误用。下面我们分别来看一下whether和 if 的用法。 一、只用 whether 的情况: 1 在表语从句和同位语从句中只能用whether表“是否”。如: He answered my question whether he would come . The news whether our team has won the game is not known. The question is whether the book is worth baying. 2 当主语从句位于主语位置上时,只能用whether表“是否”。如: Whether it will rain is not clear . Whether they will come in time is a question . 3 在介词后面引导宾语从句表“是否”,只能用whether。如: It all depends on whether they will support us . The discussion focused on whether they would buy a new car . 4 后面直接跟动词不定式时,只能用whether表“是否”。 如: I don’t know whether to stay or not. . 5 后面紧跟or not 时。如: We didn’t know whether or not she was ready . 6 引导让步状语从句时,只能用whether 。如: Whether you like it or not ,you must do it well . 7 用if会引起歧义时。如: Please let me know if you like it . 这个句子可有两个意思:“请告诉我你是否喜欢。”或“如果你喜欢,请告诉我。”用whether就可以避免歧义。 二、只用 if的情况 1引导条件状语从句时。如: If it doesn’t rain tomorrow , we will go hiking . If you like it , you can take it . 2 和 even连用时。如: Even if the job was difficult , they did it well . Even if it’s sunny , it a bit cold . 三、if , whether 均可使用的情况 1 引导宾语从句。如: I wonder if / whether the news is true or not . 2 在 “ be + 形容词 ”之后。如: He was not sure if / whether it is right or not . 3 主语从句中使用了形式主语it,主语从句后置时。如: It hasn’t been decided if / whether we shall have a class meeting . |