To find the size of the global language learning market, specifically, by the following segments: Online and offline language learning, tought language, student's language proficiency level, and type of service e.g., online tutor, app, courses, etc. For each segment, provide the revenue and the number of students. In addition, provide the number of global English as a foreign/second language students by proficiency level. The research will be used in an investor pitch deck for a startup.