Experienced English teacher online with PhD degree

I am a native English speaker and an English teacher online, with teaching experience of about 35 years. I have a PhD degree in Mathematical Linguistics. I have been teaching English for more that 12 years in Preply, one of the most popular and famous educational companies in the World. I have conducted more than 9000 English lessons in Preply with the students who live in almost all countries of the World. I have received about 260 positive feedbacks from my students. This experience gave me the opportunity to develop my own super effective system to teach English. I offer many types of courses. Besides the Course of General English, I offer also a Course of English Grammar and a Course of Conversational English, as well as a Course of Business English. I believe that one of the most interesting courses I teach is one that includes information about the largest American cities and museums, in the country where I live.