isn't "il suo" used for formal form of "you" instead of "il tuo"?
It can be used that way as well, but note that because this is mainly a text based program, we differentiate between the two by capitalizing Suo for formal you. If you see "suo" lowercase, it is either she, he or it.
Why not «pullover»?
"Sweatshirt" is also not accepeted.