Ability and Permission: móc, umieć, potrafić, wolno, można

English has one overworked word — can — that covers learned skills (I can swim), momentary possibility (I can see you now), and permission (Can I leave?). Polish refuses to blur these. It uses móc for situational ability and permission, umieć and potrafić for skills you have learned, and the impersonal można and wolno for general possibility and permission. Picking the wrong one doesn't just sound foreign — it can change the meaning entirely. This page gives you the decision rule and the conjugations to back it up.

móc — "can" in the sense of possibility or permission

móc is the closest thing to a general modal "can." It means you are able to do something in a given situation, or that you are allowed/permitted to. It is followed by an infinitive and is irregular — note the ó in the infinitive and the alternating stem:

The g of mogę / mogą softens to ż in the middle persons (możesz, może, możemy, możecie) — a classic Polish consonant alternation. Watch the spelling: it is ż (z with a dot), not rz or z.

So móc answers two of English "can"'s jobs: is it possible in this situation? and am I permitted? What it does not do is express a learned skill — for that you need umieć.

umieć — "know how to" (a learned skill)

umieć means you have learned to do something — you possess the skill. English hides this inside "can" (I can swim, I can read Polish), but Polish marks it with a separate verb. It is conjugated like a regular -em / -esz verb, with one quirk in the oni form:

The oni form is umieją (not umią — a common slip even among natives, but standard Polish wants umieją).

Notice the crucial difference: Umiem pływać = "I have learned to swim, I am a swimmer." Mogę pływać = "I'm able to swim right now" — perhaps the pool is open, the weather is fine, the doctor cleared me. The first is a permanent skill; the second is a momentary possibility.

potrafić — "be capable of, manage to"

potrafić overlaps heavily with umieć but leans toward capability and managing to pull something off, often with a hint of effort or impressiveness. It conjugates like umieć in its endings (potrafię, potrafisz, potrafi, potrafimy, potraficie, potrafią). It is biaspectual, so it covers both "be capable of" and "manage to (this once)."

Where umieć states bare skill possession (umiem gotować — "I can cook"), potrafić foregrounds the capacity to actually deliver (potrafię ugotować obiad dla dziesięciu osób — "I'm able to cook dinner for ten"). In everyday speech the two are often interchangeable for skills; reach for potrafić when you want to stress capability or, with negation, a failure to manage.

można — impersonal "one may / can"

można is the impersonal counterpart of móc: subjectless, never conjugating, followed by an infinitive. It states that something is generally possible or generally permitted — "one can," "you can" (generic), "it's OK to."

Use można when there is no specific subject — you are asking or stating about possibility in the abstract. Past is można było, future można będzie. Czy można? on its own ("May I?") is a polite, all-purpose request, e.g. reaching for the last cake or entering a room.

wolno — impersonal "be allowed" (and its negation)

wolno is the impersonal predicate of permission. It means "it is permitted / allowed," takes a dative experiencer for who is allowed, and is followed by an infinitive. Its negation nie wolno is the standard way to say "must not / it is forbidden."

The dative experiencer is optional: nie wolno tu wchodzić (general prohibition) vs nie wolno ci tu wchodzić (you specifically must not). This is the construction English speakers need for "must not" — see the negation trap on the Obligation page, where nie musieć ("don't have to") is wrongly used for prohibition.

The decision rule

Common Mistakes

The number-one error: using móc for a learned skill. Mogę pływać is grammatical but says the pool is open or the doctor cleared you — not that you know how. Skills are umieć / potrafić.

można is impersonal: always + infinitive, never a finite verb. If you want a real subject, use móc: Czy mogę tu palić?

The experiencer of wolno (and trzeba) goes in the dative: mi, ci, jej, nam — not the subject pronouns ja, ty.

Don't overshoot into umieć. Situational possibility ("I can come," "I can stay") is móc. Reserve umieć for things you have actually learned to do.

Standard Polish wants umieją in the third-person plural. Umią is heard colloquially but is non-standard (regional/colloquial).

Key Takeaways

• móc (mogę, możesz, może, możemy, możecie, mogą) = situational ability and permission, + infinitive.
• umieć (umiem… umieją) = a learned skill ("know how to"). potrafić = capability / managing to.
• można = impersonal "one may/can" (general possibility/permission), + infinitive, no subject.
• wolno = impersonal "be allowed" + dative experiencer; nie wolno is the standard "must not / forbidden."
• The split English "can" hides is skill (umieć) vs situational possibility/permission (móc/można) — get that and the rest follows.