Uncle is to aunt as father is to mother.
Sister-in-law describes a female. Brother-in-law describes a male.
The opposite relationship of uncle would be Niece or Nephew.(The opposite gender is aunt.)
his father died when he was young so he was sent of this his aunt's and uncle's
The son of your aunt and uncle is your first cousin.
Great great aunt/uncle. To your niece, you are the aunt/uncle, to her child you would be the great aunt/uncle. So you would then be the great great aunt/uncle of her child's child (her grandson)
In spanish, aunt is tia and uncle is tio.
I saw your aunt and uncle
Your niece will call you her aunt or uncle.
Your uncle's sister is your aunt, or possibly your mother.
Not of their own; this is one of the reasons they took young John in.
In Portuguese aunt is spelled Tia (you pronounce it chia) and uncle is tio(you pronounce it chi-o)