There are many non-English speaking scientists which their scientific research is amazing. However, sometimes their writing is not good. As an author, I found that I had lots of grammatical errors in my unpublished manuscript and when referee asked for correction, I corrected them. However, if a manuscript is very good in topic and awful in English, what is your first impression as a referee? Are you judge its scientific part with its English? Once, I faced a amazing referee who corrected my whole manuscript line by line and told me if you want to transfer this article to somewhere else, first correct these errors. However, I think most of referees don't have time for such detailed correction. As a referee, English is important for me also. Just want to know your comments about this topic.
Best
Somayeh