初中英语中的复合句包括定语从句、状语从句和名词性从句。定语从句修饰名词或代词，如"The girl who is singing in the choir is my best friend."；状语从句修饰主句中的动词、形容词、副词，如"She will be late for school if she doesn't hurry up."；名词性从句可以作为主语、宾语、表语、同位语等成分，如"What he said in the meeting is very important." 掌握好复合句的用法，能让英语表达更丰富、准确。
1. 定语从句
定语从句是修饰名词或代词的从句，通常用关系代词who, whom, whose, which, that引导。下面是一个例句：
- The girl who is singing in the choir is my best friend. (唱诗班里唱歌的女孩是我最好的朋友。)
解析：定语从句who is singing in the choir修饰girl。
2. 状语从句
状语从句是修饰主句中动词、形容词、副词的从句。常见的状语从句有时间状语从句、条件状语从句、原因状语从句、结果状语从句等。下面是一个例句：
- She will be late for school if she doesn't hurry up. (如果她不赶快，她会迟到。)
解析：状语从句if she doesn't hurry up修饰主句中的will be late for school。
3. 名词性从句
名词性从句可以在句子中作主语、宾语、表语、同位语等成分。常见的名词性从句有主语从句、宾语从句、表语从句、同位语从句等。下面是一个例句：
- What he said in the meeting is very important. (他在会议上说的话非常重要。)
解析：名词性从句what he said in the meeting作主语。
