The Accusative of Time and Duration | Czech Grammar

One of the quiet surprises of Czech is that "for three hours" or "all night" needs no preposition at all. Where English reaches for for, Czech simply puts the time expression in the bare accusative — the case of the direct object, used here without anything in front of it. This page covers that construction, the closely related "every…" frequency phrases, and how the bare accusative differs from the two prepositions English speakers tend to confuse it with: za and po.

The core idea: the accusative answers jak dlouho?

When you want to say how long something lasted — the whole span an action filled — you put the duration phrase in the accusative with no preposition. It answers the question jak dlouho? ("how long?").

Spal jsem celý den a večer jsem byl pořád unavený.

I slept all day and in the evening I was still tired.

Celou noc jsem nemohl usnout, soused poslouchal hudbu.

All night I couldn't fall asleep — the neighbour was playing music.

Čekal jsem na tebe celou hodinu, kde jsi byl?

I waited a whole hour for you — where were you?

In English, for is doing real work in "I waited for an hour." In Czech that for simply isn't there: Čekal jsem hodinu. Adding a preposition is the single most common mistake here — there is nothing to translate for with. The accusative ending is the "for."

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If you can ask "how long?" about the phrase, use the bare accusative — no preposition. Jak dlouho jsi spal? — Celý den. The case ending carries the "for" all by itself.

Which endings actually change

Here is the practical good news: for most time words, the accusative looks identical to the dictionary form, so there is nothing to remember. The masculine inanimate and neuter time words don't change at all.

Gender	Phrase	Looks like nominative?
masculine inan.	celý den, celý týden, celý rok	yes — unchanged
neuter	celé ráno, celé léto, celé odpoledne	yes — unchanged
feminine	celou noc, celou hodinu, celou zimu	no — celá → celou

The only forms you have to actively produce are the feminine ones, where -á → -ou (celá → celou, jedna → jednu, každá → každou). The noun itself often stays put (noc stays noc), but the adjective or quantifier in front of it must move to the accusative.

Celé léto jsme strávili u babičky na vesnici.

We spent the whole summer at grandma's in the village.

Pršelo celou noc, ráno byly všude louže.

It rained all night; in the morning there were puddles everywhere.

Počkám jednu minutu a pak jdu pryč.

I'll wait one minute and then I'm leaving.

"Every…" — frequency is also the accusative

The same bare accusative covers každý ("every") to express how often something happens. Again the feminine shifts to -ou and the rest stays put.

Phrase	Gender	Meaning
každý den / týden / rok	masc.	every day / week / year
každé ráno / pondělí / léto	neut.	every morning / Monday / summer
každou středu / sobotu / hodinu	fem.	every Wednesday / Saturday / hour

Každé pondělí chodím na jógu a cítím se po ní skvěle.

Every Monday I go to yoga and I feel great afterwards.

Každou středu máme v práci poradu hned v devět ráno.

Every Wednesday we have a meeting at work right at nine in the morning.

Babičce volám každý týden, většinou v neděli večer.

I call my grandma every week, usually on Sunday evening.

Note that the days of the week behave by their own gender: středa and sobota are feminine (každou středu, každou sobotu), while pondělí is neuter (každé pondělí) and čtvrtek is masculine (každý čtvrtek).

When numbers get involved

With dva, tři, čtyři the counted noun stands in the plural and the whole phrase still works as a bare accusative of duration.

Bydleli jsme v Brně tři roky, než jsme se přestěhovali do Prahy.

We lived in Brno for three years before we moved to Prague.

From pět upward the numeral forces the noun into the genitive plural — but that is the numeral's doing, not the time construction's, and there is still no preposition. So you get pět hodin, deset let, dvacet minut, all without for.

Ten film trval skoro tři hodiny, ale vůbec mě nenudil.

That film lasted almost three hours, but it didn't bore me at all.

The full rules for what a number does to its noun live on the numbers and case page; here just remember that the absence of a preposition is the time signal.

The contrast with za + accusative: "in / within"

Czech keeps two ideas apart that English blurs into "in." The bare accusative says how long something lasted; za + accusative says how long until something happens — the gap before a future event, or the time it takes to finish something.

Neboj, přijdu za hodinu, jenom musím něco zařídit.

Don't worry, I'll come in an hour — I just have to sort something out.

Autobus jede za pět minut, musíme si pospíšit.

The bus leaves in five minutes, we have to hurry.

Compare the pair directly: Učil jsem se hodinu = "I studied for an hour" (the accusative — that is how long it lasted). Přijdu za hodinu = "I'll come in an hour" (za — that is the gap before it happens). Same word hodinu, opposite meanings, and the difference is entirely the little za.

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English "in an hour" is treacherous. "I read it in an hour" (it took me an hour) and "I'll be there in an hour" (one hour from now) are both za hodinu in Czech — but "I read for an hour" is the bare accusative hodinu. Decide whether you mean a span filled or a gap before, then choose.

The contrast with po: "after a span" — and the emphatic "all … long"

Po + locative marks the point after a stretch has elapsed — "an hour later," "a year on." The noun goes into the locative (hodina → hodině, rok → roce).

Po hodině to vzdal a šel domů, nikdo nepřišel.

After an hour he gave up and went home — nobody showed up.

Po roce jsme se zase potkali, jako by se nic nestalo.

A year later we met again, as if nothing had happened.

There is also a po + accusative that intensifies the bare-accusative duration: po celý den = "all day long," po celou noc = "all night long." It is a heightened, slightly more emphatic version of plain celý den — both are correct, and po here still takes the accusative, not the locative.

Pršelo po celý víkend, takže jsme nikam nešli.

It rained all weekend long, so we didn't go anywhere.

Common mistakes

❌ Čekal jsem pro hodinu.

Incorrect — there is no word for 'for'; the accusative carries it.

✅ Čekal jsem hodinu.

I waited (for) an hour.

❌ Spal jsem celý noc.

Incorrect — noc is feminine, so the quantifier must be celou, not celý.

✅ Spal jsem celou noc.

I slept all night.

❌ Učil jsem se za hodinu na zkoušku.

Incorrect — za hodinu means 'in an hour's time'; for duration drop the za.

✅ Učil jsem se hodinu na zkoušku.

I studied for an hour for the exam.

❌ Chodím na jógu každý středu.

Incorrect — středa is feminine, so 'every' is každou.

✅ Chodím na jógu každou středu.

I go to yoga every Wednesday.

❌ Přijdu pro hodinu.

Incorrect — 'in an hour' is za hodinu, never pro hodinu.

✅ Přijdu za hodinu.

I'll come in an hour.

Key takeaways

Duration ("for how long") is the bare accusative with no preposition: celý den, celou noc, hodinu, tři roky. The ending replaces English for.
Only the feminine changes shape: -á → -ou (celá → celou, každá → každou, jedna → jednu). Masculine inanimate and neuter look like the dictionary form.
"Every…" frequency phrases use the same accusative: každý den, každé pondělí, každou středu.
za + accusative = "in / within" (a gap before something, or the time to finish it): za hodinu, za pět minut.
po + locative = "after a span" (po hodině); the emphatic po + accusative (po celý den) means "all day long."

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