兄弟のような
They are loving brothers.
I have many brothers and sisters―(と言うよりも普通)―I am one of a large family―I belong to a large family.
The brothers are all alive.
兄弟の子
stepbrothers
Do you have any brothers?
They are half-brothers―half-sisters.
They are cousins.
The brothers are at variance with each other.