How do you say hello and goodbye in Irish?

Hello

• Dia dhuit (singular)
  
• Dia dhaoibh (plural)
  
• Dia is Muire dhuit (singular reply)
  
• Dia is Muire dhaoibh (plural reply)
  

Goodbye

• Slán
  
• Slán go fóill
  
• Slán agat (to one peron who is staying)
  
• Slán agaibh (to more than one person who is staying)
  
• Slán leat (to one person who is leaving)
  
• Slán libh (to more than one person who is leaving)
  
• Feicfidh mé ar ball thú (singular, See you later)
  
• Feicfidh mé ar ball sibh (plural, See you later)
  
• Chífidh mé ar ball thú (singular, See you later) - Ulster
  
• Chífidh mé ar ball sibh (plural, See you later) - Ulster