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