There is no verb ‘to have’, Instead, use prepositional pronouns and the verb ‘to be’
aig – at
agam – at me
agad – at you
aige – at him
aice – at her
againn – at us
agaibh – at you
aca – at them
Tha cat agam = I have a cat.
Tha cat agad = You have a cat
A bheil clann aice? Does she have any children?
Chan eil clann aice = She doesn’t have any children.
A bheil peata agad? = Do you have any pets?
A bheil cat agad? = Do you have a cat?
A bheil cU agad? = Do you have a dog?
A bheil cAr agad? = Do you have a car?
A bheil clann agad? = Do you have children?