Phone Numbers, Counting Out Loud and Ages | Czech Grammar

This page covers the numbers you actually say out loud every day: reading a phone number to someone, counting on your fingers, and telling your age. Each of these has a small Czech twist that catches English speakers — the way digits are grouped, the special counting form of "one," and an age construction that literally says "to me is twenty years."

Phone numbers — read in groups of three

A Czech mobile number has nine digits and is conventionally written and read in three groups of three: 601 234 567. You don't read it digit by digit by default — you read each three-digit group as a whole number.

Group	Read as
601	šest set jedna
234	dvě stě třicet čtyři
567	pět set šedesát sedm

Moje číslo je šest set jedna, dvě stě třicet čtyři, pět set šedesát sedm.

My number is six-oh-one, two-three-four, five-six-seven.

When clarity matters — dictating to someone who's writing it down, or reading over a bad line — Czechs switch to digit by digit, and then "1" is said as jedna. You can also read in two-digit pairs, but the three-by-three grouping is the everyday default.

Diktuju ti to po číslicích: šest, nula, jedna, dva, tři, čtyři, pět, šest, sedm.

I'll dictate it digit by digit: six, zero, one, two, three, four, five, six, seven.

Counting out loud: jedna, dva, tři

When you just count — on your fingers, counting objects, reciting the sequence — the neutral form of "one" is the feminine jedna. This is the default citation form children learn and the form you use when no particular noun is attached.

Počítej se mnou: jedna, dva, tři, čtyři, pět!

Count with me: one, two, three, four, five!

There's a second, (informal) set you'll hear for rhythm and cadence — counting people in, exercising, dancing, doing a countdown: raz, dva, tři. Here raz replaces jedna and means "one" purely as a beat, never as a quantity. You'd never say raz to count apples; you say it to set a tempo.

Raz, dva, tři – a teď zatáhni!

One, two, three – and now pull!

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Use jedna to count things ("how many?") and raz only as a beat ("ready, set…"). Raz is colloquial cadence — fine in the gym or on the dance floor, out of place when you're actually tallying a quantity.

jeden / jedna / jedno — "one" agrees like an adjective

Unlike the higher numbers, "one" agrees in gender with the noun it counts, exactly like an adjective. There are three forms in the nominative:

Gender	Form	Example
masculine	jeden	jeden rohlík (one roll)
feminine	jedna	jedna otázka (one question)
neuter	jedno	jedno pivo (one beer)

Dám si jen jeden rohlík, nemám velký hlad.

I'll just have one roll, I'm not very hungry.

Mám jenom jednu otázku, pak už vás nechám být.

I have just one question, then I'll leave you be.

Na celý zájezd zbývá poslední jedno místo.

There's one last place left for the whole trip.

This is a real difference from dva, tři, čtyři, pět, which don't bend for gender this way (apart from dva/dvě). With "one," always match the noun's gender first.

"number X" — číslo + a plain cardinal

To name a number — a bus, a room, a house — Czech uses číslo ("number") followed by a plain cardinal in the nominative. Crucially this is the cardinal (pět, dvanáct), not the ordinal (pátý, dvanáctý).

Jeďte autobusem číslo devět, staví přímo před nádražím.

Take bus number nine, it stops right in front of the station.

Bydlíme v domě číslo dvanáct, ta zelená branka.

We live at number twelve, the green gate.

House numbers, room numbers, and bus or tram lines are all read as cardinals like this. (What does take ordinals is the floor — třetí patro, "third floor" — and dates and clock times, which are covered on the ordinals page.) In very casual speech a tram or bus line often becomes a noun in its own right — jedu devítkou ("I'm taking the number 9") — but the neutral form is číslo devět.

Telling your age: "to me is twenty years"

Czech does not say "I am twenty." It says, literally, "to me is twenty years" — the person goes in the dative and the verb is být ("to be"). This frame trips up English speakers because both the case and the verb feel unexpected.

Person (dative)	Age frame
já → mi	Je mi dvacet let.
ty → ti	Kolik je ti let?
on → mu	Je mu deset let.
ona → jí	Je jí třicet let.

Je mi třicet pět let a cítím se skvěle.

I'm thirty-five and I feel great.

Kolik je ti let? – Mně? Dvaadvacet.

How old are you? – Me? Twenty-two.

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Don't translate "I am twenty" word for word — Jsem dvacet is wrong. Reset your mental template to "to me is twenty years": the person lands in the dative (mi, ti, mu, jí) and the verb is být. Once that frame is automatic, only the rok/roky/let ending is left to choose.

The rok / roky / let split

The word for "year" changes shape with the number, and the change is partly irregular — there's no clean logic, you memorise the three buckets:

Number	Word for "year(s)"	Verb	Example
1	rok	je (sg.)	Je mi jeden rok.
2, 3, 4	roky	jsou (pl.)	Jsou mi tři roky.
5 and up	let	je (sg.)	Je mi pět let.

The surprise is the form let for five and above. It is a suppletive genitive plural — historically it comes from a different word (léto, "summer"), not from rok at all. You can't derive it; you simply have to know that "five years" is pět let, never pět roků. The same let is used for all the compound numbers too: dvacet jedna let, čtyřicet let, sto let.

Naší dceři jsou tři roky a synovi je teprve rok.

Our daughter is three and our son is only one.

Babičce bude příští týden osmdesát let, chystáme oslavu.

Grandma will be eighty next week, we're planning a celebration.

Tomu autu je už dvacet let, ale pořád jezdí.

That car is already twenty years old, but it still runs.

Notice that the dative age frame works for any owner, not just people — Tomu autu je dvacet let puts the car itself in the dative.

Common mistakes

❌ Je mi pět roků.

Incorrect — five and up takes the suppletive let: pět let.

✅ Je mi pět let.

I'm five years old.

❌ Jsem dvacet let.

Incorrect — Czech uses the dative frame, not 'I am': Je mi dvacet let.

✅ Je mi dvacet let.

I'm twenty years old.

❌ Je mi tři roky.

Incorrect — 2, 3, 4 take the plural verb jsou: Jsou mi tři roky.

✅ Jsou mi tři roky.

I'm three years old.

❌ Jeďte autobusem číslo devátý.

Incorrect — 'number nine' uses the cardinal devět, not the ordinal.

✅ Jeďte autobusem číslo devět.

Take bus number nine.

❌ Mám jeden otázku.

Incorrect — otázka is feminine, so 'one' is jedna.

✅ Mám jednu otázku.

I have one question.

Key takeaways

Phone numbers are read in three groups of three (601 234 567 → šest set jedna, dvě stě třicet čtyři, pět set šedesát sedm); switch to digit-by-digit when dictating.
Counting things uses jedna, dva, tři; the cadence count raz, dva, tři is (informal) and only marks rhythm.
"One" agrees in gender: jeden (m), jedna (f), jedno (n) — unlike the higher numbers.
"Number X" = číslo + cardinal (číslo devět), and house/room/line numbers are cardinals; floors and dates are ordinals.
Age uses the dative frame Je mi … let and the irregular rok (1) / roky (2–4) / let (5+) split, where let is a suppletive form you must memorise.

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