复杂句和复合句都有两个句子组成，复合句中，两个句子独立表达完整的意思，能独立存活。复杂句由一个主句和一个从句组成,其中的从句不能独立表达一个完整的意思。
扩展资料
复合句
复合句分为并列复合句（也称并列句）和主从或从属复合句（也称复杂句）。
Beijing is in the North and Nanjing is in the South.
特点：When two independent clauses, or complete sentences are joined together, they form one compound sentence.
复合句是由两个独立的`句子组合在一起构成的。例句中，有下面两个完整并且独立的句子组成：
Beijing is in the North.
Nanjing is in the South.
复杂句
复杂句，某个句子成分直接由从属分句表示，那么这种句子便不是简单句而是复杂句。
My uncle, who is seventy years old, works on a farm.
特点：When an independent clause and a dependent clause are joined together; they form one complex sentence.
复合句是由一个独立的句子加一个从句构成的。
China is a country that its history is very long.
China is a country.(独立句子)
That its history is very long(从句)
