I went out to communicate in my senior year and junior year. Are you a translator, business English or a foreigner? Is it a compulsory course that credits can't be transferred back after you come back, or is it that credits can be transferred enough, but some courses are not lacking and you want to take it?

If you can't transfer credits for certain courses, you can apply to the educational administration teacher in the first week of your senior year, and then make up that course. If you just want to listen, just tell the teacher in class, and the teacher doesn't mind.