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

Yes, it is pretty easy to tell when someone is foreign to the English language. It's also pretty easy to tell when a native speaker of English is also foreign to the language. None of it really matters though. If you apply the principle of charity to someone's expression, you do your best to try and grasp the intent of the message regardless of how formally correct it is. And as others have said, irregular English patterns by non-native speakers are actually quite charming.

So where is the OP from? It’s “writing”. Not “writting”. 

"I recently joined a Asian audiophile Facebook group..."

AN Asian audiophile Facebook group?

So few of the super hot chicks speak Latin

Abre la boca, sagua la lingua!