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4th Conjugation (-VENI) 

venio, venire, veni, ventum

Note that these verbs are all compounds of the intransitive verb venio. Nevertheless, not all of the verbs in this episode are intransitive. A few verbs are transitive. Listen carefully to the fourth principal part to determine whether the verb is more likely to be intransitive (vent-um) or transitive (invent-us).