Is easy to know when a non english speaker is writting?

Great to see people from all over the world participate here. 

I recently joined a Asian audiophile Facebook group, mainly to read some feedback on a speaker I want to get. It turns out that people on this  Facebook group has some amazing systems. Google translate is also my friend.

Once upon a time I wanted to be a Linguistics professor.  I actually got an M.A. in the discipline before my life made a thoroughly enjoyable left turn.  At any rate, my masters thesis focused on English Grammar.  And lemme tell ya.  When it comes to grammar, English is a veritable rats' nest.

frigging gringos are trying to figure out my accent... hilarious !  

Yes. But I really enjoy what one of the above posters refers to as offbeat syntax. A few years ago, I was on a music forum and a French lady reacted to a particular new record by saying "I'm on the ninth cloud." Turns out she was saying the equivalent of "Cloud 9." I enjoyed that expression so much that I drop it on people every once in a while. The blank stares are hilarious.

Yes its easy to identify a non-native speaker unless of course they speak and write perfect English.  I know a woman from Belgium who speaks perfect English with no accent at all.  But she's the only European I've ever known who did not have any accent.