cause
The German word 'Ursache' translates to 'cause' in English. It is used to describe the reason or origin of an event, action, or phenomenon. For example, 'Die Ursache des Feuers war ein Kurzschluss' (The cause of the fire was a short circuit).
The cause of the problem is still unknown.
This sentence implies that there is a problem, but the reason or source of it has not been identified yet.
Cause and effect are not always obvious.
In this statement, the speaker is suggesting that determining the source of a situation and its result can sometimes be difficult or unclear.
The cause of his anger was unclear.
This implies that the person being discussed is angry but the reason for this anger is not apparent or understood.