I am a French national. I have 33 years of experience in English, both British and American. I have worked with children for 32 years as a home educator, lived abroad , ie India and am used to several different English pronunciations: British, American, Australian, New Zealand, Indian, some African Countries. I can understand as well Shakespearian English and read it (I read the King James Bible, unabridged edition).
I also own a Certificate in Advanced English with the University of Cambridge. And I will be looking into getting the Proficiency one as this is more my actual level in English.