定语是用来修饰名词或代词的，一般放在这两种词的前或后。分别叫做前置定语和
后置定语。the book on the desk is mine. /the girl dancing in the room is our monitor.
this is a difficult problem.
表语放在
系动词后，表示主语的性质，状态或特征。it is fine./ they are students. / he is out.
补语包括宾补和
主补。宾补在宾语后用来说明宾语怎么样或宾语是什么，做什么，宾语的状态等。he told us to follow him. / we should make our classroom clean.
主补是补充说明主语是什么，做什么或怎么样的。可放在句子中间或末尾。
he was told to work ten hours a day.
状语是用来修饰动词。形容词，副词和整个句子的。可放在句子中间，句子开头或结尾要看是哪种副词做状语，
频度副词常放在行为动词前。如i often do some reading in the evening。方式副词放在句尾如he speaks English well.
程度副词放在形容词或副词前如，
the boy is very tall
he runs very fast.
评论性副词放在句首或句尾。如Luckily, he passed the exam.