This form is used independently, not with a noun that it modifies. It is always preceded by the particle a.
- a ceathair, a cúig, a sé – "four, five, six"
- bus a ceathair – "bus number four"
- a ceathair a chlog – "four o'clock"
- ceathrar (used to modify a noun referring to human beings)
- ceithre (used to modify a noun not referring to human beings)
- ceathair déag
- ceathrú (ordinal)