umět vs moci vs znát

English collapses an enormous amount of meaning into the little word can and the verb know. "I can swim," "I can come tomorrow," "I know him," "I know how to cook" — Czech refuses to let these blur together. It uses umět, moci/moct, and znát for what English treats as one or two words, and choosing the wrong one is one of the most reliable ways to sound like a foreigner. The good news is that the split is logical: each verb owns a clearly defined slice of meaning. Once you can sort a sentence into the right slice, the verb chooses itself.

This page covers the three modality-adjacent verbs that English speakers confuse: umět (a learned skill), moci/moct (ability or possibility in the circumstances), and znát (acquaintance). A fourth verb, vědět ("to know a fact"), belongs to the same family but answers a different question; it is treated in full on the four-way moci / umět / znát / vědět page, and we point you there rather than duplicate it here.

The quick answer

Ask yourself what kind of "can" or "know" you mean:

• umět
  • infinitive — a skill you have learned and now possess. Umím plavat. (I can swim / I know how to swim.)
• moci / moct
  • infinitive — you are in a position to do something right now: circumstances, permission, possibility. Můžu ti pomoct. (I can help you.)
• znát
  • accusative object — you are acquainted with a person, place, or thing. Znám ho. (I know him.)

umět — a learned skill

Umět means you have acquired an ability and carry it with you: swimming, driving, cooking, a language, a craft. The thing is true of you in general, regardless of today's circumstances. It is followed by an infinitive, or — uniquely — by a language name directly, with no infinitive at all.

The language construction is worth memorising on its own. With a language, umět takes the adverb form (česky, anglicky, německy), not the noun:

Notice that English here says "speak," not "know how to" — but the underlying meaning is a learned skill, so Czech still reaches for umět.

Present tense of umět: umím, umíš, umí, umíme, umíte, umějí (colloquially also uměj/umí). It is a regular -ět verb of the prosí class; see the class-I conjugation.

moci / moct — ability in the circumstances

Moci (literary infinitive) / moct (everyday spoken infinitive) is the verb of circumstance and permission. It does not ask whether you have a skill; it asks whether the situation lets you. You can be a perfectly able driver (umím řídit) and still say dneska nemůžu řídit because you've been drinking. That contrast is the heart of the distinction.

That last example shows the permission sense, which English also expresses with can/may. Moct covers it naturally.

The contrast with umět in one breath:

The first clause is a permanent skill (umím); the second is today's situation (nemůžu). Swapping them is ungrammatical in meaning even if the words look fine.

Moct is irregular (a velar-stem verb): můžu/mohu, můžeš, může, můžeme, můžete, můžou/mohou; past mohl, mohla, mohli. The můžu/můžou forms are normal speech; mohu/mohou are bookish. Its full paradigm and the moci/moct doublet live on the moci/moct page.

znát — to be acquainted

Znát is not a modal verb at all — it takes a direct object in the accusative, not an infinitive. It means you are acquainted with a person, place, or thing: you've met them, been there, encountered it. It is the "know" of familiarity, the French connaître, the German kennen, the Spanish conocer.

Because znát demands an object, it can never be followed by an infinitive. You cannot znát how to do something — that is what umět is for.

Present tense: znám, znáš, zná, známe, znáte, znají — a fully regular -á verb.

All four at once

A short scene shows how cleanly the verbs divide the work. Note the fourth verb, vědět ("know a fact"), slotting in alongside the others:

• Umím vařit — a learned skill.
• dneska nemůžu — today's circumstances forbid it.
• znám restauraci — acquaintance with a place (accusative object).
• vím, že je otevřená — knowledge of a fact (followed by a že-clause).

For the vědět half of the picture in full — including vím / víš / ví and the contrast between knowing a fact and being acquainted — go to the four-way page.

A decision flowchart

1. Is there an infinitive after "can"? → it's a skill or a circumstance.
   • A learned ability true of you in general → umět (umím plavat).
   • Possibility, permission, or today's situation → moct (můžu přijít).
2. Is "know" followed by a person, place, or thing (a noun)? → znát (znám ho).
3. Is "know" followed by a fact (a že- or kde/kdy-clause)? → vědět (see the four-way page).

Common mistakes

Using moct for a skill is the classic English-transfer error. "I can swim" feels like can, so learners reach for můžu — but a skill is umět.

Using znát with an infinitive, on the model of English "know how to":

Using umět when you mean today's circumstances rather than a skill:

Using vědět for acquaintance with a person — a frequent slip because both are "know":

Putting a noun directly after umět for "know a language" instead of the adverb:

Key takeaways

• umět = a learned skill
  • infinitive (or a language as česky/anglicky): Umím plavat. Umím česky.
• moct/moci = circumstance, possibility, permission
  • infinitive: Můžu přijít. Můžu si vzít?
• znát = acquaintance
  • accusative object: Znám ho. Znám Prahu. Never with an infinitive.
• Skill ≠ circumstance: Umím řídit (skill) vs Nemůžu řídit (today).
• For "know a fact," use vědět
  • a clause — see the dedicated four-way page.