As an editor who works quite a bit in the sciences, I have had the experience several times of working with multi-language authors.
Multi-language authors were formerly called “nonnative English speakers” by me and many other editors who worked with them. The proper terminology has recently changed. I have to admit that at first I sniffed at this, since I thought it was the editing world’s attempt to be “politically correct.”
Ah, but since then I have been educated.
First of all, multi-language authors are just that; they speak English and at least one other language. I personally speak conversational French and can write at maybe the seventh-grade level in it, so technically I am a multi-language author. I hesitate to bestow that title upon myself, however, since my command of French is somewhat limited.
How many English-language authors can write in another language? (Notice that I did not say “foreign language.”) Quite a few, I am certain. But I am also certain that there are several who cannot.
The one thing you should not do if you are editing an English-language document written by a multi-language author is laugh at the author or put them down because they “don’t know how to write.” Ask yourself this: Can you write in their language? I always remind myself that my Chinese (or Russian, or whatever language) isn’t nearly as good as the author’s English.
Humbling thought.