There’s a remark that I see once a while in reviews, something along the lines of: “The authors should have their work edited by a native English speaker.”
Please stop staying this. I think it’s a problem, for three reasons:
First, as a reviewer, you have absolutely no idea whether the author(s) are native English speakers. There isn’t a box that in the manuscript submission process that asks this question. You can’t infer this information from a name, or an institution, or a geographic location. This is an assumption that you don’t need to make.
Second, there are many ways to be a native English speaker. If a manuscript is written differently than you would write it, and you think there are lots of grammatical errors, this doesn’t mean the author isn’t a native English speaker. It just means their English is different than what you think is acceptable.
Third, telling authors that they can’t publish their work without going through someone of your own cultural background is a textbook example of gatekeeping. This kind of approach tells fellow scientists that they’re not welcome in our scientific community unless they have a cultural escort. You might not think that’s what “have your grammar checked by a native English speaker” means, but that’s definitely how some people see it. You don’t need to say it, so, please, just don’t.
So, then, you might be wondering, what should you say instead? If you think a manuscript needs to be fixed, say so. Just say what the problem is.
Don’t make it about the author, make it about the manuscript, in a polite and straightforward manner. For example, “There were several places where the subject-verb agreement was incorrect (e.g., lines 147 and 233), and a few sentences that I had trouble following. I think detailed copyediting would be helpful.”
I’ve got to tell you that, on multiple occasions, I’ve seen reviews saying that the authors are not native English speakers when I knew for an absolute fact that the authors were native English speakers. In one case, the author grew up only speaking English in the US, and went abroad for a postdoc, and then a reviewer didn’t like some of the grammar and just assumed the author wasn’t a native English speaker. But even if a person is not a native English speaker (perhaps you know them and discussed this previously), you still shouldn’t indicate this as a limitation in the review. Because there are a ton of people who are not native English speakers who have amazing English grammar in their scientific writing. It’s not about being a native speaker. It’s about writing a manuscript in English. Whether or not you’re a “native” doesn’t matter at all, so keep that out of it.
In your review, do you need to do careful copyediting to improve the writing? No, you clearly are not expected to do this, you’re being asked to review the science. It would be generous of you to spend your time on copyediting, but it’s okay to just write a single sentence in the review saying how the writing needs some attention.
What do you do if the manuscript is nonsensical enough that you can’t evaluate the science? You should return it to the editor with out a review, saying that you couldn’t understand it. Then the editor can ask the author to revise to make it understandable. If you genuinely can’t understand it, you shouldn’t review it. However, I think these situations are very rare. I think some people just see grammar they don’t like and then get all fed up.
The bottom line is that when we review manuscripts, we don’t need to make assumptions about the authors. We shouldn’t make assumptions about the authors. We should focus on the manuscript itself.