英语语法中,主语后的从句可以是名词性从句、定语从句或状语从句。名词性从句作为宾语,通常由“that”、“whether”、“if”等引导。定语从句修饰主语,常由“who”、“whom”、“whose”、“which”、“that”等引导。状语从句修饰谓语或整个句子,常由“when”、“while”、“after”、“because”、“if”等引导。使用主语后的从句时,注意从句与主句的语法关系和连接词的选择使用。
名词性从句
名词性从句是一种在主语后面作为宾语的从句。它可以充当名词的角色,通常由连接词“that”、“whether”、“if”等引导。例如:
- I know that he is a good student.(我知道他是个好学生。)
- She asked whether we would come to the party.(她问我们是否会来参加派对。)
- He asked me if I had finished my homework.(他问我是否完成了作业。)
定语从句
定语从句是一种在主语后面修饰主语的从句。它通常由关系代词“who”、“whom”、“whose”、“which”、“that”等引导。例如:
- The girl who is wearing a red dress is my sister.(穿红色连衣裙的女孩是我妹妹。)
- The book which I borrowed from the library is very interesting.(我从图书馆借来的那本书非常有趣。)
- The man whose car was stolen called the police.(车被盗的那个人报警了。)
状语从句
状语从句是一种在主语后面修饰谓语或整个句子的从句。它通常由连接词“when”、“while”、“after”、“because”、“if”等引导。例如:
- She sings while she works.(她工作时会唱歌。)
- After I finish my homework, I will watch TV.(我完成作业后,会看电视。)
- If it rains tomorrow, we will stay at home.(如果明天下雨,我们会呆在家里。)