I remember some reviews of suggested edits where the reviewers clearly could not understand either the post or the edit.
One of these was http://askubuntu.com/a/476746/117103 , supposedly an answer, which it isn't. I don't blame anybody for not understanding Italian - but it isn't at all useful to "improve" a non-answer of the species "I have the problem too".
So please: If you don't understand a post or the suggested edit, be it
- because of a language barrier
- because you are not familiar with the topic
- because the subtleties escape you
- ...
don't hesitate to press the 
button!
As has been suggested I want to add that the same applies to all review queues - although the reason language barrier will not be so frequent there :-)