How “cé leis” works
Ownership in Irish is said with le: is liom é, it is mine. So whose is cé leis, and the answer keeps le: is le Máire é, it is Máire's; is liomsa é, it is mine.
séimhiú or h urú or t-
céwho
+leiswith him / it
=
Cé leis é?Whose is it?
“Cé leis” in questions
Cé leis é seo?
Whose is this?
Cé leis an carr sin?
Whose is that car?
Cé leis na bróga seo?
Whose are these shoes?
Is liomsa é.
It is mine.
Is le Máire é.
It is Máire's.
Ní liomsa é.
It is not mine.
Other question words
Whose in Irish (cé leis): the questions people ask
How do you answer cé leis é?
With le and the owner: is liomsa é (mine), is leatsa é (yours), is le Seán é (Seán's). Not mine is ní liomsa é.