(Rare, Usual) (Seldom, Often)

[kahhong]

Hello... what are the differences between Rare, Usual Seldom, Often?
Im confused..

[Tdol]

Rare & usual- adjectives- It's rare/usual for him to be late.
Seldom & often- adverbs- He's seldom/often late
In terms of meaning, rare & usual are oppsites, as are seldom & often