Hello Peter， 英语&英文 sometimes are interchangeable. But 英语 is English language, always focuses on speaking English language and emphasizes on a kind of language. 英文 is a specific style of English, always focuses on English characters. Here are some examples about 英语&英文： 1. --- 你的母语是什么？ --- 我的母语是英语。 ---What is your native language ? ---My native language is English. 2. --- 这篇文章是用什么语言写的？ --- 这篇文章是用英文写的。 --- What language was the article written in？ --- The article was written in English. I hope my answers can be helpful for you, if you have any problems about Chinese, just let me know. ^_^ Anna

hello peter， generally speaking，英语 and 英文 could be interchangeable. however, as far as I know, the people who live in the Mainland China prefer to use 英语, while the people who live in Taiwan prefer to use 英文. They also use 法文（French ）instead of 法语。 hope my answer can help.

Yes, they are interchangeable. 英文is slightly more formal than 英语