英语中有两种从句，分别是宾语从句和定语从句。它们都是由一个引导词引导的从句，但它们在句子中的作用不同。
宾语从句
宾语从句是在主句中作宾语的从句。宾语从句通常由连词that, if, whether, who, whom, whose, what, when, where, why, how等引导。
以下是一些宾语从句的例子：
- I know [that you love me].
- He asked [whether you could come to the party].
- She wonders [what the answer is].
- They don't know [who stole their car].
- He told me [how to get to the train station].
在宾语从句中，主语和谓语的顺序通常是颠倒的，即谓语动词在主语前面。另外，宾语从句中的时态和语态也要根据主句的要求进行调整。
定语从句
定语从句是在主句中作定语的从句。定语从句通常由关系代词who, whom, whose, that, which等引导。
以下是一些定语从句的例子：
- The man [who is standing over there] is my brother.
- The book [that I borrowed from the library] is very interesting.
- The car [which is parked outside] belongs to my neighbor.
- The girl [whose parents are doctors] is very smart.
- The dress [that she is wearing] is very pretty.
在定语从句中，从句中的主语和谓语通常是不颠倒的，即谓语动词在主语后面。另外，定语从句中的关系代词在句中可以作主语、宾语、表语或定语。此外，关系代词可以省略，但是在口语中经常省略，在正式的写作中应该尽量避免。
总之，掌握宾语从句和定语从句的结构和用法是学习英语的重要一环。只有深入理解并在实际运用中多加练习，才能在英语表达中更加自如和准确。
