Not all verbs can form the passive voice. The most important verb categories that have no passive types are displayed below.
| verb categories | Examples |
| modal verbs | müssen, können |
| reflexive verbs | sich irren, sich interessieren |
| transitive verbs | |
| the accusative object indicates size, quantity, etc. | kosten, enthalten o.ä. |
| the impersonal "es gibt" | es gibt |
| verbs kennen, wissen | kennen, wissen |
| intransitive verbs | |
| verbs whose subject is not a person | Ihre Art gefällt uns. |
| verbs with a subject that does not really denote action | Die Kinder schlafen. |
| verbs that form the present perfect with sein | Sie kommen spät zurück. |