Survenir belong to the 3rd group. Survenir is a common french verb.
Survenir is conjugated the same way that verbs that end in : -enir
Survenir is conjugated with auxiliary être.
Survenir verb is
intransitive.
Survenir is a french third group verb. So, this verb is irregular and do not follow a regular conjugation pattern like first or second group verbs. Follow this link to see all the endings of the conjugation of most of the third group verbs : conjugation rules and endings for the second group verbs.
Verbs derived from tenir and venir form a major group of verbs who gains a d in the future and conditional. These verbs are the only verb to have a nasal vowel in the past historic and imperfect subjunctive.
SURVENIR : v. intr. Arriver inopinément, venir tout à coup. Comme ils étaient ensemble, il survint du monde. S'il me survient des affaires. Comme nous étions prêts à partir, un orage survint. Il signifie aussi Arriver de surcroît. S'il survenait le moindre accident, il n'y aurait plus aucun espoir de le sauver.