Hello there, Sophina.
The following Knowledge Base article should help you answer this:
To view if an iTunes Gift has successfully been redeemed, navigate to your Account Settings from the iTunes Store, and click "Manage Gifts" in the Purchase History. From this page, you will also have the option to edit the recipient address, and resend the gift (if not already redeemed):
Thanks for reaching out to Apple Support Communities.
No longer accurate, at least on OS X:
And clicking View (next to the item/app) just shows the option to Resend gift, which maybe implies if you can Resend, it hasn't been Received (they haven't accepted, whatever)?