Irish:
Dia Dúit - (God be with you) Hello
Cad é mar atá tú? - How are you?
Slán agat/agaibh - Goodbye (said when you are leaving a person[s] company)
Slán leat/libh - Goodbye (said to the person[s] that's leaving)

More Norwegian:
Hei - Hello
Hvordan går det med deg/dere? - How are you?
Ha det bra (Ha det) - Goodbye

B.