Breakdown of Du darfst das Fenster keinesfalls in der Nacht offen lassen.
die Nacht
the night
du
you
das Fenster
the window
dürfen
may
Questions & Answers about Du darfst das Fenster keinesfalls in der Nacht offen lassen.
Why is dürfen used here instead of können or sollen?
In German, dürfen expresses permission or prohibition: what you are (not) allowed to do.
- du darfst … = you are allowed to … / you may …
- du darfst das nicht … = you are not allowed to … / you must not …
So in this sentence, du darfst … keinesfalls means you are absolutely not allowed to ….
Compare:
- du kannst das Fenster nicht offen lassen – you cannot / are not able to leave the window open (focus on ability).
- du sollst das Fenster nicht offen lassen – you should not leave the window open (a recommendation or instruction).
- du darfst das Fenster nicht/keinesfalls offen lassen – you may not / must not leave the window open (a rule or prohibition).
Here, the idea is clearly “not allowed”, so dürfen is the natural verb.
What exactly does keinesfalls mean, and how strong is it?