Formal/Respectful:
* -hood: Fatherhood (the state of being a father)
* -ship: Fathership (less common, but similar to fatherhood)
Informal/Affectionate:
* -y: Daddy (used by children and in some contexts by adults)
* -ie: Daddie (less common, but sometimes used in a playful or affectionate way)
Other:
* -ly: Fatherly (describes qualities of a father)
* -ing: Fathering (the act of being a father)
It's important to note that the choice of suffix depends on the context and intended meaning.