dürfen: Permission and Prohibition

dürfen is the German modal of permission. At its core it answers the question "Am I allowed to?" — but its two most important uses are the ones English handles clumsily: negated nicht dürfen is the German way to say "must not" (prohibition), and the Konjunktiv II form dürfte is a polite way to say something is probably true. Mastering those two keeps you from the most common English-speaker mistakes.

Conjugation in the present

Like all the core modals, dürfen changes its vowel in the singular (the umlaut disappears: dürf- becomes darf-) and takes no -t ending in the third person singular.

PersonForm
ichdarf
dudarfst
er / sie / esdarf
wirdürfen
ihrdürft
sie / Siedürfen

The infinitive that dürfen governs goes to the very end of the clause, forming the Satzklammer (sentence bracket): the modal sits in second position, its partner verb waits at the end.

Darf ich hier rauchen?

May I smoke here? (asking permission)

Kinder dürfen den Film nicht sehen.

Children are not allowed to watch the film.

Ihr dürft jetzt nach Hause gehen.

You may go home now. (informal, to a group)

Permission: "to be allowed to"

The default meaning of dürfen is permission granted by someone or something external — a rule, a parent, the law, your host. This is exactly where English speakers reach for can, and that habit is the first thing to break.

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English uses can for both ability and permission ("Can I go?"). German keeps them apart: können = ability, dürfen = permission. Asking Kann ich gehen? literally questions whether you are physically able to leave; Darf ich gehen? asks whether you are allowed to.

Du darfst mein Auto nehmen, kein Problem.

You're allowed to take my car, no problem. (informal)

Hier darf man nicht parken.

You're not allowed to park here.

In a restaurant or shop, the polite offer Was darf es sein? is a fixed phrase — literally "what may it be?", meaning "what can I get you?". The staff is offering permission to order.

Was darf es sein?

What can I get you? (set phrase, formal service register)

Prohibition: nicht dürfen = "must not"

This is the single most important thing on this page. nicht dürfen does not mean "don't have to" — it means must not. It withdraws permission and forbids the action.

Du darfst hier nicht rauchen.

You must not smoke here. (it is forbidden)

Patienten dürfen vor der Operation nichts essen.

Patients must not eat anything before the operation. (formal)

English "must not" feels like it belongs to must, so learners instinctively negate müssen to express prohibition. That is wrong, and the error is dangerous because nicht müssen means the opposite — "don't have to."

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Map it carefully: müssen = "must / have to," but nicht dürfen = "must not." Negating müssen gives you "don't have to," not "must not." So Du musst nicht kommen means "You don't have to come," while Du darfst nicht kommen means "You're not allowed to come." See the müssen page for the full contrast.

Präteritum and Perfekt: the past

In the simple past (Präteritum), dürfen is weak and predictable: the stem is durf- (short u, no umlaut), and you add weak endings.

PersonPräteritum
ich / er / sie / esdurfte
dudurftest
wir / sie / Siedurften
ihrdurftet

Als Kind durfte ich nie lange aufbleiben.

As a child I was never allowed to stay up late.

In speech, the Präteritum is by far the normal way to talk about past permission. The Perfekt exists but is comparatively rare. When dürfen governs a main verb in the Perfekt, German uses the double infinitive (Ersatzinfinitiv): dürfen, not the participle gedurft.

Ich habe leider nicht mitkommen dürfen.

Unfortunately I wasn't allowed to come along.

Only when dürfen stands alone, with no governed verb, does the real participle gedurft appear:

Das hätte ich nicht gedurft.

I shouldn't have been allowed to do that.

This split — infinitive with a partner verb, participle when alone — is the heart of the Perfekt-and-double-infinitive page.

dürfte: polite probability

Here is the use that competitors skip and that English covers only loosely. The Konjunktiv II of dürfen is dürfte, and it does not mean "would be allowed." It expresses a cautious, educated guess — "probably," "is likely to."

PersonKonjunktiv II
ich / er / sie / esdürfte
dudürftest
wir / sie / Siedürften
ihrdürftet

Das dürfte stimmen.

That's probably true.

Er dürfte jetzt schon zu Hause sein.

He's probably home by now.

Die Reparatur dürfte ungefähr 300 Euro kosten.

The repair will likely cost around 300 euros.

The logic is that Konjunktiv II steps back from plain fact into the realm of inference, so dürfte reads as "if I had to guess, I'd be allowed to conclude that…". It is more confident than könnte ("could/might") and far more measured than the bald present tense. English "may/might" overlaps with this, but English has no single word that carries the same "I'm fairly sure but hedging politely" flavour — which is exactly why learners forget to use it.

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Remember the three faces of one verb: present darf = "is allowed," past durfte = "was allowed," but Konjunktiv II dürfte = "probably." The umlaut on dürfte is your signal that you have left permission behind and entered probability.

Common mistakes

❌ Kann ich auf die Toilette gehen?

Wrong if you mean permission — this literally asks about your physical ability.

✅ Darf ich auf die Toilette gehen?

May I go to the toilet? (permission)

❌ Du musst hier nicht rauchen.

Wrong for a smoking ban — this means 'you don't have to smoke here.'

✅ Du darfst hier nicht rauchen.

You must not smoke here. (it's forbidden)

❌ Er darf reich sein.

Wrong if you mean 'he's probably rich' — this says he's allowed to be rich.

✅ Er dürfte reich sein.

He's probably rich. (cautious inference)

❌ Ich habe nicht kommen gedurft.

Wrong — with a governed verb, use the infinitive dürfen, not the participle.

✅ Ich habe nicht kommen dürfen.

I wasn't allowed to come.

❌ Darfst du schwimmen?

Wrong if you mean 'can you swim?' — this asks for permission, not ability.

✅ Kannst du schwimmen?

Can you swim? (ability)

Key takeaways

  • dürfen = permission; do not use können to ask whether you are allowed.
  • nicht dürfen = "must not" (prohibition). Negating müssen gives "don't have to" — the opposite.
  • Present darf, past durfte, standalone participle gedurft, double infinitive dürfen with a partner verb.
  • dürfte (Konjunktiv II) is a polite probability marker — "probably," not "would be allowed."

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Related Topics

  • Modal Verbs: OverviewA2The six German modal verbs, their shared word order, and the irregular present tense that makes ich and er identical.
  • können: Ability, Possibility, PermissionA2The full conjugation and meanings of können — ability, possibility and informal permission — plus the könnte / konnte trap that turns on a single umlaut.
  • müssen: Necessity and ObligationA2The full conjugation and meaning of müssen — plus the meaning-reversing negation trap: nicht müssen means 'needn't', and English 'must not' is darf nicht.
  • Konjunktiv II of Modal VerbsB1könnte, müsste, dürfte, sollte, möchte — the high-frequency modal subjunctives behind polite and tentative German, and the umlaut that separates them from the plain past.
  • dürfen: Full Conjugation and UsageA2Complete conjugation of the modal verb dürfen 'may / to be allowed', the double-infinitive Perfekt, and why 'nicht dürfen' — not 'nicht müssen' — is the way to say 'must not'.
  • Expressing Certainty, Doubt, and ProbabilityB2The full German epistemic scale from certain to doubtful — adverbs like bestimmt, wahrscheinlich, vielleicht and möglicherweise, the false friend eventuell, and the distinctly German use of modal verbs (muss, dürfte, könnte, mag) and Futur I (wird wohl) to express how likely something is.