Bellingham has quickly established himself in Dortmund's midfield after his summer move from Birmingham City.
He told Kicker: "I have to work on my game overall, tactically and technically. But also mentally. I can still improve in all areas. My goal is to achieve that."
The teenager also has no plans of returning to England anytime soon.
“To be honest, I'm not even thinking about that at the moment. It feels great to play for BVB. I don't have a career plan or anything in mind either. I live in the moment and every day I take it as it comes. Today I concentrate on training, on Wednesday on the game against Zenit. I don't think much further."