For anyone who wants to improve your pronunciation for any languages, knowledge of phonetics is required. There are books and a course. The process usually takes you about 1 year to practice. Books: A course in phonetics (Peter Ladefoged) Handbook of the IPA (the official handbook) A MOOC course (in English): https://www.youtube.com/watch?v=BI_ywtB3wLY&list=PLCX-BLZ1hDpCWfv4UrMiAX4qGg9rC0W6m