German : passive voice
When the subject of a sentence is doing the action, the verb is said to be in the active voice, but when the subject is on the receiving end of, or suffering, the action, the verb is said to be in the passive voice.
This is formed in German by the auxiliary " werden" PLUS the past participle.
Ich ärgere meine Frau (I annoy my wife.) active
Meine Frau wird von mir grärgert. (passive )
ONLY transitive verbs can be made passive, intransitive verbs have NO passive.
The passive can be avoided by other constructions.
Note that the auxiliary " werden" is NOT confined to the formation of the future and conditional tenses.