Awesome... thanks, you two. I am new, so I really appreciate all the help :)
da? Why not de?
'da' indicates a relationship with quantity or number. 'de' indicates possession. Since the tea doesn't own the cup, 'da' makes more sense.
"taso da teo" = a cupful of tea, a cup of tea (quantity)
"taso de teo" = a teacup, a cup used for tea (but may be empty)