In Hindi you want 'to' something. "मुझे खाना चाहिए" literally means "To me food want", but it's the equivalent of "I want food".
Why is "the" necessary. why not "Peter does not want a knife." Knife is a generic object. There arany knives. There is no unique knife called "The knife".
batesita, ko is a connecting word. it connects objects and subjects and also indicate the the action/response of the subject.