Sure. You can say all of these in American English. * at the dinner table at home * Dad: What do you want to drink? Do you want milk? Son: Yes, I'll have milk. / Yes. I want milk. * at a restaurant* Waitress: What can I get you to drink? Mother: Okay, listen up, everyone. What do you all want to drink? 6 y/o son: I want milk! 8 y/o son: I want Coke! 6 y/o son: No, wait! I want Coke too! 8 y/o daughter: I want Sprite! 18 y/o son: I'll have a water without lemon. * Saying "want" to a waitress here is a little forward/rude though, in my opinion. Hence, why the 18 y/o in my example said "I'll have". I think this is how most adults order something at a restaurant. The younger kids are all screaming out their desires with the mother though. :)

Yes, the book is using "standard grammar" by asking the questions in that way.

Thanks for reply. Well it's passage in a kids' story. it goes like this: A lazy cat is beeing asked: do you want milk? (cat): yes please. do you want bread? yes please do you want to run? no thanks

In what context? If you're getting ready to go to the supermarket and you're offering to buy these things for someone at home, then it sounds fine. Otherwise, you'd probably need a different phrase. Are you asking if you can omit "some"?