复合句是英语写作中的重要组成部分，它们通过连接词如and、or、but等将两个或多个简单句或从句连接起来，使句子结构更加复杂和丰富。以下是一些关于复合句的英语作文示例：

简单句与复合句的结合

Everyone has his or her own hobby. Today I am going to talk about my hobby. My hobby is swimming. I like it very much, although I don't swim very well. And I go to swim with my friends.

使用条件状语从句

Unless he comes, we won't be able to go.

Suppose it goes on raining, what shall we do？

使用时间状语从句

As long as I am alive, I shall go on studying.

使用让步状语从句

Although he was ill, he kept on working.

使用并列连词连接句子

The bell is ringing and the lesson is over.

使用从属连词引导从句

The girl felt nervous with so many people staring at her.

With the teacher's help, he made great progress.

使用复合句表达比较

Liu Yifei is the most beautiful girl that I have ever seen in my life.

合并句子

You must get over your lesson. You will fail in the exam.

Professor Wang gave us a lot of advice. He helped us to study English.

通过这些示例，可以看到复合句在英语作文中的多样性和实用性。它们不仅能够使句子更加流畅和连贯，还能表达更复杂的逻辑关系。在写作时，合理运用复合句可以提升文章的质量和表达的深度。