Interesting topic. To me, a US'n from the midwest, a cupboard is anything pertaining to storage of kitchen items(dishes, pots and pans, dry goods, cleaning supplies). These are usually fixed to the walls, but not always. A wardrobe is a detached closet, a piece of furniture almost exclusively for the storage of clothing. In Spanish, a wardrobe is called ropero, clothing = ropa. I'm not remembering cupboard in Spanish right now, only trastero, the cupboard where dishes are stored. Roperos are much more prevalent in Mexico than closets, while the reverse is true where I live now.