Contenir belong to the 3
rd group. Contenir is a common french verb.
Contenir is conjugated the same way that verbs that end in :
-enir
Contenir is conjugated with
auxiliary avoir.
Contenir verb is
direct transitive.
French verb contenir can be conjugated in the reflexive form:
Se contenir
Contenir verb is a direct transitive verb, so passive voice can be used.