Rétrécir belong to the 2nd
group. Rétrécir is a common french verb.
Rétrécir is conjugated the same way that verbs that end in : -ir
Rétrécir is conjugated with auxiliary avoir
Rétrécir verb is
direct transitive, intransitive.
French verb rétrécir can be conjugated in the reflexive form: Se rétrécir
verb is a direct transitive verb, so passive voice can be used.