One thing you should keep in mind: Not everyone is blessed with "lingual talent". Einstein as he immigrated to the States and taught in English...He had a heavy German-accented English and in many cases he spoke more "Deuglish" (Deutsh = German, hence Deu-glish) than English.
The main thing is as our little boss @alway5dotcom wrote
It's about THE communication between human and human. It's NOT about a competition about whom who speaks the most correct, the most accent-free and the best English. Even English people have bad language. If you had to chance to listen to Londoner dialect called Cockney English (HERE for more to smile) you wouldn't believe that it was English. Some still speak Cockney in Londoner pubs.