Perhaps you should try some spelling variations:
passiveen » passiveand, passively, passiver
passiverer » passiverwerb, passiver, passagerer
passieren » passiert
passiven » passion
passivieren » passivierende, passivierung, passagieren

You may be able to get more results by adjusting your search query.

• If you are trying to use Boolean operators, they must be ALL CAPS: (passive OR (passiveen OR ((passiverer OR (passieren OR passiven)) OR passivieren))).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(passive or (passiveen or ((passiverer or (passieren OR passiven)) or passivieren)))".
• Adding a wildcard symbol may retrieve word variants: (passive or (passiveen or ((passiverer or (passieren OR passiven)) or passivieren)))*.