Irregular Present: jíst and vědět | Czech Grammar

Two of the most everyday Czech verbs — jíst "to eat" and vědět "to know (a fact)" — refuse to follow any of the regular conjugation classes. They are short, they are irregular, and you will use them dozens of times a day, so they repay a few minutes of focused memorisation. They also share one oddity that trips up nearly every learner: a third-person plural that ends in -dí (jedí, vědí), where you would expect -jí or -í. This page drills the present tense of both; for the full picture in every tense, follow the verb-reference links.

jíst — to eat

The present tense of jíst runs on a long í for five of the six persons, then springs a surprise in the third plural, where the stem changes to jed-:

Person	Form	English
já	jím	I eat
ty	jíš	you eat
on / ona / ono	jí	he / she / it eats
my	jíme	we eat
vy	jíte	you (pl./formal) eat
oni / ony / ona	jedí	they eat

The form jedí is the one to burn in: not *jí repeated, not *jíjí, but jedí, with the stem switching from jí- to jed-. That same jed- stem returns in the past — the participle is jedl, jedla, jedlo, jedli, jedly, jedla (note the neuter plural jedla) — and in the imperative jez! / jezte! "eat!".

Co jíte k snídani?

What do you have for breakfast?

Děti jedí pomalu, počkáme na ně.

The kids eat slowly, let's wait for them.

Maso jím jen občas, většinou vařím bez něj.

I eat meat only occasionally; I usually cook without it.

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Don't confuse the soundalikes: jí "he/she eats" vs. jí "to her" (a dative pronoun) vs. jdi "go!". They look close but live in different sentences — context always tells them apart.

The aspect pair jíst / sníst

Jíst is imperfective — the verb for eating as an ongoing or habitual activity. Its perfective partner is sníst, "to eat up / finish eating," which conjugates the same way (sním, sníš, sní, sníme, sníte, snědí) and has the past participle snědl. Use sníst when the food is finished off in one completed go.

Snědl jsem celou pizzu sám.

I ate a whole pizza by myself.

The contrast is the standard imperfective–perfective one: Jím oběd "I'm eating lunch (in progress)" vs. Sním oběd "I'll eat (all) my lunch (completed)." The pair is treated in full on jíst / sníst.

vědět — to know (a fact)

Vědět follows the same skeleton as jíst: a short paradigm built on ví-, with the third plural breaking to věd-:

Person	Form	English
já	vím	I know
ty	víš	you know
on / ona / ono	ví	he / she / it knows
my	víme	we know
vy	víte	you (pl./formal) know
oni / ony / ona	vědí	they know

Again the third plural is the danger zone: vědí, not *ví and not *vějí. The past participle restores the věd- stem too: věděl, věděla, vědělo, věděli, věděly, věděla. If you line the two verbs up — jím / jedí, vím / vědí — the parallel makes both easier to remember: short stressed root throughout, then a -dí plural with a fuller stem.

Vím, kde to je, půjdu napřed.

I know where it is, I'll go ahead.

Nevím, jestli dnes přijde.

I don't know whether he's coming today.

Víš, kolik je hodin?

Do you know what time it is?

Notice what vědět takes as its complement: a clause (vím, že… "I know that…"; vím, kde / kdo / jestli… "I know where / who / whether…") or the neuter pronoun to (vím to "I know it/that"). It points at information — facts, answers, whether-or-not. It does not normally take a person or a place as a direct object.

vědět vs. znát vs. umět: three verbs for English "know"

English flattens three different ideas into the single word know. Czech keeps them apart, and choosing the wrong one is one of the most common A2 errors. Match the verb to what is known:

Verb	You know…	Takes	Example
vědět	a fact / piece of information	a clause or to	Vím, že přijde.
znát	a person, place, thing (be acquainted with)	an accusative object	Znám ho.
umět	how to do something (a skill)	an infinitive or skill-object	Umím plavat.

Vím to, ale neřeknu ti to.

I know it, but I won't tell you. (a fact → vědět)

Znám ho už roky, chodili jsme spolu do školy.

I've known him for years, we went to school together. (a person → znát)

Umíš vařit, nebo budeme jíst venku?

Can you cook, or are we eating out? (a skill → umět)

The clean test: if you could rephrase with "I know that…" or "I know whether/where/who…", use vědět. If you could add "I'm familiar with…", use znát. If you could swap in "I know how to…", use umět. The whole tangle is mapped out on moci / umět / znát / vědět.

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A useful pair to memorise side by side: Vím to "I know it (the fact)" vs. Znám to "I know it (I'm familiar with that place/song/thing)." Same English "I know it," two different Czech verbs — the choice depends entirely on whether to is a fact or a thing.

Common Mistakes

The errors cluster around the -dí plural and the three-way "know" split.

❌ Děti jí ve školce.

Incorrect — 'jí' is singular; the subject 'děti' is plural.

✅ Děti jedí ve školce.

The kids eat at nursery. (3rd plural → jedí)

❌ Oni vějí všechno.

Incorrect — invents a regular -jí plural.

✅ Oni vědí všechno.

They know everything. (3rd plural → vědí)

Using vědět where Czech wants znát (knowing a person, not a fact):

❌ Vím tvoji sestru.

Incorrect — you can't 'know a fact' that is a person.

✅ Znám tvoji sestru.

I know your sister.

And the reverse — znát where the object is a fact or clause:

❌ Znám, že máš pravdu.

Incorrect — a 'that'-clause is a fact, so it needs vědět.

✅ Vím, že máš pravdu.

I know you're right.

Finally, a spelling-and-length slip: these stems carry a long vowel (jím, víš), and shortening it to *jim, *vis changes or destroys the word (jim is actually the dative "to them").

❌ Vis, co tím myslím.

Incorrect — short vowel; 'vis' is not the verb.

✅ Víš, co tím myslím.

You know what I mean.

Key Takeaways

jíst: jím, jíš, jí, jíme, jíte, jedí — third plural jedí, past stem jed- (jedl).
vědět: vím, víš, ví, víme, víte, vědí — third plural vědí, past stem věd- (věděl).
Both keep a long vowel through most of the paradigm and break to a -dí plural — memorise that plural deliberately.
vědět = know a fact (clause / to); znát = know a person/place/thing (accusative); umět = know how to (skill).

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