Can someone explain : why is it "i ndeisceart NA hÉireann " but " i lár AN leathanaigh" for example. How can we know when it is "an" and when it is "na" for the same genitive?
In the genitive case, na is the singular definite article for feminine nouns. Éire is a feminine noun, therefore X na hÉireann, and leathanach is a masculine noun, therefore X an leathanaigh.
Why is it "an leathanaigh" and not "na leathanaigh"?
leathanach is a masculine noun, so its genitive singular form uses an.
Go raibh maith agat!