i had a very good seat.
主语 谓语 定语 宾语
The play was very interesting
主语 系动词（谓语） 表语
.I didn’t enjoy it
主语 助动词+谓语 代词做宾语
A man and a woman were sitting behind me.
主语 系动词（过去进行时） 状语 补语
They were talking loudly
主语 系动词（过去进行时） 副词修饰动词做表语
楼主 够详细了吧