I have / I don't have Target sentences:

Q) An bhfuil peann agat? Do you have a pen? (Lit. Is there a pen at you?).
+) Tá peann agam. I have a pen.
-) N íl peann agam. I don't have a pen.

ag at
agam at me
agat at you (singular)
aige at him, it
aici at her, it
againn at us
agaibh at you (plural)
acu at them
Tá punt aige. He has a pen.
Tá teach againn. We have a house.
Tá madra aici. She has a dog.
Tá peann acu. They have a pen.
Tá briseadh ag Lorcán. Lórcan has change.
An bhfuil peann ag Lorcán? Does Lórcan have a pen?
Tá/Níl peann aige. He doesn't have a pen.

Phrase of the week:
Níl fhios agam. I don't know.
Níl fhios agam ón spéir anuas. I haven't a clue.