[Sometimes as a threat:
Il aura affaire à moi = He will have to deal with me.]
Avoir affaire de quelqu’un = To need a person.
[“J’ai affaire de vous, ne vous éloignez pas.”]
Avoir son affaire = To have what suits one. J’ai mon affaire = I have found what I want. J’ai votre affaire = I have got the very thing for you. Il aura son affaire (ironic.) = He will catch it.
C’est toute une affaire = It is a serious matter; It means a lot of bother (or, trouble).
C’est une affaire faite = It is as good as done.
Son affaire est faite = He is a dead man (of one dying); He is done for; He is a ruined man.
Faire son affaire = (of oneself) To succeed. Il fait tout doucement son affaire = He is getting on slowly but surely.
(Of others) To punish. S’il le rencontre, il lui fera son affaire = If he meets him he will give it to him, will “do” for him.