Q: The father convinced his son that it is possible for him to one day become a knight, but he may never achieve such status coming from a peasant family.
Who he is?
A: his son

Q: The dog hunted the fox because it was hungry.
Who it is?
A: The dog

Q: Skype has entered a partnership with Facebook, and they hope that this can help to promote their video calling.
Who they is?
A:
Skype