To show that Cumberland is the owner, a "h" is dunked after the first letter of his name e.g. "athair Chumberland" = Cumberland's father / "siopa Chumberland" = Cumberland's shop
Your brother = "do dheartháir" (singular)
His brother = "a dheartháir"
Her brother = "a deartháir"
Our brother = "ár ndeartháir"
Your brother = "bhur ndeartháir" (plural)
Their brother = "a ndeartháir"