Although a site might be in English, that does not mean the owners or users actually know the language.
Some are just learning it, some think they know it, and when it is not a moderated site, or the moderators don’t really know English, many mistakes will happen.
You can easily ascertain this by what is posted. It is often funny to see how words are misused and not caught.
Once you realise that the site is in English because many users use that language and it is easier to deal with Pay Pal or Adsense as an ‘American’ based site, you develop a kind of tolerance.
The person reading your comment or article might not comprehend what you are saying. He or she might leave some confused response, or more usual, a cut and pasted empty compliment.
Before attacking with both barrels, ascertain if they speak and understand English.
Often you have to rephrase in tiny words so to be certain that you are understood and you understand what they have posted.
Errors can lead to vicious attacks when one thinks you said…. when in truth you posted the opposite.