Indeclinable Nouns | Czech Grammar

After all the case endings Czech throws at you, here is a small mercy: a set of nouns that never change form at all. They are mostly foreign borrowings whose endings don't fit any native declension class, so the language simply leaves them alone. taxi is taxi in every case; menu is menu whether it's the subject, the object, or after a preposition. The catch — and it is the whole point of this page — is that the case still has to be expressed. Czech just shifts the job onto the words around the noun: the demonstrative, the adjective, the verb. The noun freezes; its companions decline.

Which nouns stay frozen

The reliable rule is about the ending. A borrowed noun that ends in a vowel Czech never uses to start a declension — -i, -í, -é, -ú, -u, -y, -ø (a stressed final vowel) — has nowhere to attach endings and stays indeclinable. Compare: borrowings ending in -o and -a get pulled into Czech declension (auto → auta, kino → kina, drama → dramatu), but the ones below do not.

Noun	Gender	Meaning
taxi	neuter	taxi
menu	neuter	menu
alibi	neuter	alibi
kupé	neuter	compartment (train)
klišé	neuter	cliché
tabu	neuter	taboo
jury	feminine	jury, panel
whisky	feminine	whisky
paní	feminine	Mrs, lady, madam

Each one still has a gender, assigned for agreement even though you can't read it off an ending. Taxi, menu, alibi, kupé, klišé are neuter (to taxi, to menu); jury and whisky are feminine (ta jury, ta whisky). You learn the gender along with the word, exactly as on the guessing gender from the ending page — except here the ending gives you no hint, so it is pure memory.

The case is marked on the modifiers

This is the mechanism to internalise. When an indeclinable noun needs a case, the demonstrative and adjective carry it. The noun is a fixed point; everything around it bends.

To nové menu vypadá výborně.

The new menu looks excellent. (nominative — to nové are nominative; menu unchanged)

V tom menu nebylo nic vegetariánského.

There was nothing vegetarian on that menu. (locative — v tom marks the case; menu unchanged)

Jel jsem domů tím posledním taxi.

I went home in that last taxi. (instrumental — tím posledním are instrumental; taxi unchanged)

Bez pořádného alibi se z toho nedostaneš.

Without a solid alibi you won't get out of this. (genitive — pořádného is genitive; alibi unchanged)

Notice that in every sentence the case is fully present — to / v tom / tím / bez … pořádného — it has simply migrated off the noun and onto its neighbours. A listener knows the case from those words; the noun's job is just to name the thing.

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Think of an indeclinable noun as a label and the demonstrative/adjective as the grammar around it. If you remember to put ten/ta/to (or tento, or an adjective) in the right case, the sentence is correct no matter that taxi or menu never moves. The frozen noun is the easy part; getting tím / v tom / k tomu right is the work.

paní — the one you'll use most

By far the most frequent indeclinable noun is paní (Mrs, lady, madam). In the singular it does not change across all seven cases — ta paní, té paní, tu paní, s tou paní — and again the demonstrative does the marking. (In the plural it does pick up a few endings: paním in the dative, paními in the instrumental — but the singular, which you need constantly, is fixed.)

Znáte tu paní odvedle?

Do you know that lady next door? (accusative — tu paní)

Dal jsem ten dopis té paní v okénku.

I gave that letter to the lady at the counter. (dative — té paní)

Mluvil jsem s paní učitelkou o synovi.

I spoke with the teacher about my son. (paní stays put; učitelkou carries the instrumental)

That last example shows the pattern with a title: in paní učitelka, paní doktorka, paní Nováková, the paní is frozen and the second word declines (s paní doktorkou, k paní Novákové).

Foreign first names, too

Many foreign women's names ending in a stressed vowel behave the same way — Daisy, Betty, Mary, Naomi — they keep one form and let the surrounding words mark the case. (Czech first names and how most of them do decline are covered on the first names page.)

Šel jsem do kina s Daisy.

I went to the cinema with Daisy. (Daisy unchanged; s + instrumental sense carried by context)

Tu knížku jsem půjčil Naomi.

I lent that book to Naomi. (dative; Naomi unchanged)

Number is shown by agreement, not by the noun

Because the noun can't take a plural ending either, number also rides on the agreeing words. Two taxis is dvě taxi with a plural verb: dvě taxi stála před hotelem ("two taxis were standing in front of the hotel" — neuter plural stála).

Před nádražím stála dvě taxi.

Two taxis were standing in front of the station. (dvě … stála show the plural; taxi unchanged)

Common mistakes

❌ Seděli jsme v kupém celou cestu.

Incorrect — kupé never takes endings; the locative is v tom kupé, with the noun unchanged.

✅ Seděli jsme v tom kupé celou cestu.

We sat in the compartment the whole way. (kupé unchanged; v tom marks the case)

❌ Dal jsem si skleničku whiskoy.

Incorrect — whisky is indeclinable; you do not add an instrumental ending, it stays whisky.

✅ Dal jsem si skleničku whisky.

I had a glass of whisky. (whisky unchanged; skleničku carries the grammar)

❌ Šel jsem domů ten taxi.

Incorrect — 'by that taxi' is instrumental, so the demonstrative must decline: tím taxi.

✅ Šel jsem domů tím taxi.

I went home by that taxi. (tím taxi)

❌ Dej to menu na stůl, to nového menu.

Incorrect — the adjective must agree in case; with the noun frozen, you still say to nové menu.

✅ Dej to nové menu na stůl.

Put the new menu on the table. (to nové menu, all nominative)

❌ Mluvil jsem s paniou Novákovou.

Incorrect — paní does not decline in the singular; it is s paní Novákovou.

✅ Mluvil jsem s paní Novákovou.

I spoke with Mrs Nováková. (paní frozen; Novákovou declines)

Key takeaways

Borrowings ending in -i, -í, -é, -ú, -u, -y (and paní) are indeclinable — one form in every case. Those ending in -o / -a usually decline (auto, kino).
Each still has a gender you must memorise: to taxi, to menu (neuter); ta jury, ta whisky (feminine).
The case and number move onto the modifiers: v tom menu, tím taxi, dvě taxi stála. Get the demonstrative/adjective right and the sentence is correct.
paní is the high-frequency one: invariable in the singular; in titles the paní freezes and the second word declines (k paní doktorce).

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