"写作文"的英文翻译是 "write a composition"。例如：

1. 我们需要写一篇关于环境保护的作文。[We need to write a composition on environmental protection.]

2. 她正在练习写一篇关于家庭生活的作文。[She is practicing writing a composition about family life.]

3. 这篇作文的语法和句子结构都非常准确。[The grammar and sentence structure of this composition are very accurate.]