Forfaire belong to the 3
rd group.
Forfaire is conjugated the same way that verbs that end in :
-aire
Forfaire is conjugated with
auxiliary avoir.
Forfaire is a defective verb.
It can not be conjugated in all possible forms.
Forfaire verb is
direct transitive, indirect transitive, intransitive.
Forfaire verb is a direct transitive verb, so passive voice can be used.