Appesantir belong to the 2
nd group.
Appesantir is conjugated the same way that verbs that end in :
-ir
Appesantir is conjugated with
auxiliary avoir.
Appesantir verb is
direct transitive.
French verb appesantir can be conjugated in the reflexive form:
S'appesantir
Appesantir verb is a direct transitive verb, so passive voice can be used.