Grammar: Transitive and Intransitive Verbs
English is this very carefree language. It really doesn't care if you return (Douglas MacArthur: "I shall return!") in an intransitive way, or if you return something in a transitive way (I shall return the book tomorrow! I promise!).
Latin really does care. It pays close attentive to which verbs are transitive (take objects) and which verbs are transitive (don't take objects). As a general rule, active verbs can be transitive (but they do not have to be). Passive verbs, as a general rule, are intransitive and cannot take direct objects. The famous exception, of course, would be some deponent verbs: deponent verbs take passive endings but they can also be transitive, taking an object (ducem sequitur, he follows the leader). Aside from these special deponent verbs, Latin passives are intransitive and do not take objects.
The problem is that if you are translating from English into Latin, you might not realize that you are dealing with an intransitive verb that in Latin does require a passive form, distinguishing it from the transitive, active form. For example, the verb "to shake" in English can be transitive or intransitive:
In Latin, the intransitive "shake" is a passive form of the verb, while the transitive "shake" takes the active form: