Tum mujhe madad kiun nahi karne dete? / Aap mujhe madad kyun nahi karne dete?

How to say “Tum mujhe madad kiun nahi karne dete” in English

When you want to say “Tum mujhe madad kiun nahi karne dete?” (or “Aap mujhe madad kyun nahi karne dete?”) in English, the natural, everyday way is “Why don't you let me help?”. It fits everyday talk.