It must be quite funny to be in a company where almost nobody communicate in his native language. I've seen some russian language messages in youtrack followed by a stern response to write in english in public places.

The trick is always the same, when you use english as the common language in your company, you immediately give a strong communication power to native english speakers, they always look so confident when they speak. They look more professional by not doing mistakes, by using a wide vocabulary and by mastering the corporate lingo. That's a place where Europe could innovate: finding a third way between using English that completely obliterate non-native speakers in arguments and using hundred of translators, one for each couple of languages.