1. quién = with who do you prefer go shopping?
2. por qué = do you like bargain? why ?
3. con qué = which one do you choose to pay with: cash or credit card?
4. qué = what do you prefer to buy: souvenir for you or for someone else?
5. qué = which souvenir do you buy more: t-shirts, handicracft or something else?
6. dónde = where do you to buy clothes: mall or somewhere else?
sorry if my english it's not that well! hope it's ok