You don't need a degree to have a chat to a group of Chinese students, or to set a discussion topic and let them crack on. Because that is NOT real teaching. That is what any monkey who is a native speaker can do... It takes real teaching qualifications to actually teach and get the students to the point they can have those discussions in the first place. That teaching is what you need to be qualified for.

Although in an idea world anybody teaching should have a relevant degree and a PGCE