写作业的英语是 "do homework"。其中，“do”是动词，表示“做”或“干”；“homework”是名词，意为“家庭作业”。这个短语简洁明了，直接表达了完成学校分配的任务这一概念。

例如：

1. I have to do my homework every evening.

2. She is doing her homework right now.

3. Do your homework carefully.

4. I don't want to do my homework.

如果你需要更具体的表达，例如强调写作过程，可以说 "do writing assignments" 或 "work on written tasks"。对于不同类型的作业，还可以具体说明，如 "do math homework"（做数学作业）、"do reading assignments"（做阅读作业）或 "do science projects"（做科学项目）。