The passive voice is a verb form that is used to describe actions or conditions. It changes the perspective of an action or event. While the active sentence emphasizes the subject carrying out an action, a passive construction places emphasis on the action carried out. The agent in a passive sentence is less important, perhaps not even named. The action itself is in the foreground. To form the passive, German uses the helping verb "werden" and a past participle. The helping verb is conjugated and the past participle remains unchanged. In an simple declarative sentence, the helping verb is in the second position and the past participle goes to the end of the sentence.

Example:
Harry wird operiert.

The personal passive voice
When a passive sentence includes the person or thing to which the action is being done it is called a personal passive statement. The subject of a passive sentence is the accusative object in the corresponding active sentence.

Examples:
Active: Dr. Anderson operiert Harry.
Passive: Harry wird operiert. - Wer oder was wird operiert? - Harry.

The impersonal passive voice
If no-one or no-one in particular is named as the subject in a passive sentence, then it is called an impersonal passive statement. Such sentences frequently begin with the word "es" in place of a noun or personal pronoun. An impersonal passive statement can also begin with a different part of the sentence, in which case the "es" is omitted. Impersonal passive constructions are one of the rare instances in which a German sentence has no subject.

Examples:
Active: Man arbeitet nicht mehr unter Tage. (oder: Wir/Sie arbeiten nicht mehr unter Tage.)
Passive: Es wird nicht mehr unter Tage gearbeitet.
Unter Tage wird nicht mehr gearbeitet.

Active: Wir suchen ein Bergwerk, in dem noch jemand arbeitet.
Passive: Wir suchen ein Bergwerk, in dem noch gearbeitet wird.