OK, Let me give you an example. A few days ago I listened to an interview of an old hutsul woman. She lives high in mountains and of course speaks dialect. She went behind her daughter down the hill and said ‘ za nev’ ( in standard Ukrainian it should have been za neju ) , instead of yogo ( him ) she used nego. You can’t stop laughing when listen to such language. It is very funny and unusual. To feel and understand it you have to know some languages ( the standard one is absolutely necessary). And suddenly she inserted a Russian word in the conversation.
I am really afraid it will be not easy to recognize all those differences without basic skills of language/languages