If there is one feature of German numbers that causes more errors than all the others combined, it is this: from 21 upward, German names the units digit first and the tens digit second, joining them with und ("and"), and writes the whole thing as one word. So 21 is einundzwanzig — literally "one-and-twenty". This reverses the English order and is the source of constant phone-number and price mistakes. This page teaches the tens, the units-before-tens rule, and the three irregular tens you must spell carefully.
The tens
First, the tens themselves. They are mostly formed by adding -zig to the unit, but three of them are irregular and must be memorized as exceptions.
| Number | German | Notes |
|---|---|---|
| 20 | zwanzig | not *zweizig — irregular stem (from zwei) |
| 30 | dreißig | -ßig, not -zig! The only ten spelled with ß |
| 40 | vierzig | regular: vier + zig |
| 50 | fünfzig | regular (keep the umlaut) |
| 60 | sechzig | sechs loses its s (like sechzehn) |
| 70 | siebzig | sieben loses its -en (like siebzehn) |
| 80 | achtzig | regular: acht + zig |
| 90 | neunzig | regular: neun + zig |
| 100 | hundert | often einhundert in careful speech |
Notice that the irregularities you met in the teens come back exactly: sechzig drops the s of sechs (just like sechzehn) and siebzig drops the -en of sieben (just like siebzehn). The one genuinely new trap is dreißig — 30 is the only ten ending in -ßig (with an eszett) rather than -zig. This is a frozen historical spelling, and Germans themselves have to learn it; there is no rule to derive it from.
Mit dreißig hat sie ihre eigene Firma gegründet.
At thirty she founded her own company.
Die Fahrt dauert ungefähr vierzig Minuten.
The trip takes about forty minutes.
Tempo sechzig — das ist hier die Höchstgeschwindigkeit.
Sixty km/h — that's the speed limit here.
The big reversal: units before tens, joined by und
Here is the heart of the page. To say a two-digit number from 21 to 99, you take the units digit, then und, then the tens digit, and run them together as one word:
unit + und + ten → einundzwanzig (1-and-20 = 21)
So you literally say the number backwards relative to English. English speakers of an older era will recognize the pattern from the nursery rhyme "four and twenty blackbirds" — but in German this antique-sounding order is the only order, used by everyone, all the time, in every register.
| Number | German (one word) | Literally |
|---|---|---|
| 21 | einundzwanzig | one-and-twenty |
| 32 | zweiunddreißig | two-and-thirty |
| 43 | dreiundvierzig | three-and-forty |
| 67 | siebenundsechzig | seven-and-sixty |
| 87 | siebenundachtzig | seven-and-eighty |
| 99 | neunundneunzig | nine-and-ninety |
Two spelling details inside the compound: the unit "one" keeps its full eins-stem as ein- (einundzwanzig, with no ending — it does not become einsundzwanzig), and the whole thing is written solid, with no spaces and no hyphens, all the way up to a million. Einundzwanzig is one word; writing ein und zwanzig as three words is an error.
Meine Oma wird dieses Jahr fünfundachtzig.
My grandma turns eighty-five this year.
Das macht zusammen siebenundzwanzig Euro fünfzig.
That comes to twenty-seven euros fifty altogether.
Im Bus saßen nur dreiunddreißig Leute.
There were only thirty-three people on the bus.
Die Antwort ist zweiundvierzig.
The answer is forty-two.
Why this matters: the listening trap
This reversal is not just a writing curiosity — it actively breaks comprehension. When a German reads out a price, a phone number, or a house number, you hear the small digit first and must hold it in memory while the tens arrive. English-trained ears, primed to take digits left to right, write 76 down as 67. There is no clever shortcut: when you hear ...und... in the middle of a number, that is your signal to flip the two digits you heard. Vierundachtzig? You heard "four ... and ... eighty" → write 84, not 48.
The stakes are real and everyday. Transposing two digits turns a bus that leaves at platform 27 into one at platform 72, a price of €43 into €34, and a phone number you will never reach. Germans themselves are aware of the awkwardness: there is even a small reform movement (Zwanzig-eins) that proposes saying the digits in left-to-right order, but it has gone nowhere — einundzwanzig is what you will hear from every speaker, in every region, in every register. So the burden is on the learner's ear, not on the language. The good news is that the fix is mechanical and quick to drill: take any handful of two-digit numbers, listen to them spoken, and force yourself to write the units digit last. After a few hundred repetitions the swap stops being conscious.
Combining with hundert
The same units-before-tens logic carries straight into the hundreds, and only the last two digits reverse. So 123 is hundertdreiundzwanzig — "hundred-three-and-twenty": the hundreds come in normal order, then the final two digits swap. The full mechanics of hundreds, thousands and millions are on the next page, but it is worth seeing here that the rule you just learned scales up.
Das Buch hat hundertvierundzwanzig Seiten.
The book has a hundred and twenty-four pages.
Common Mistakes
❌ zwanzigeins / zwanzig-eins
Incorrect — English digit order; German puts the unit first.
✅ einundzwanzig
21 = 'one-and-twenty', units before tens, one word.
❌ dreizig
Incorrect — 30 is the one ten that uses ß.
✅ dreißig
Thirty is spelled with eszett: dreißig.
❌ sechszig / siebenzig
Incorrect — too many letters carried over from the unit.
✅ sechzig / siebzig
60 and 70 drop letters, just like sechzehn and siebzehn.
❌ ein und zwanzig (three words)
Incorrect — two-digit numbers are written as a single word.
✅ einundzwanzig
One solid word, no spaces, no hyphens.
❌ einsundzwanzig
Incorrect — the units 'one' loses its -s inside the compound.
✅ einundzwanzig
The stem is ein-, not eins-, when it joins a tens digit.
Key Takeaways
- Two-digit numbers run unit + und + ten, written as one word: einundzwanzig.
- This reverses English order and is the #1 cause of number errors — flip the digits when you hear und.
- Memorize the irregular tens: zwanzig (from zwei), dreißig (ß!), sechzig and siebzig (dropped letters).
- "One" inside the compound is ein- with no ending: einundvierzig, not einsundvierzig.
Now practice German
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Start learning German→Related Topics
- Cardinal Numbers 0-20A1 — The German numbers null to zwanzig, including the irregular teens elf and zwölf, the dropped letters in sechzehn and siebzehn, and why the count eins becomes ein before a noun.
- Hundreds, Thousands, MillionsA2 — Building large German numbers as single words up to a million, the reversed decimal comma and thousands dot (1.000,5), and the high-stakes false friend Milliarde = billion, Billion = trillion.
- Pronouncing Numbers, Dates, and Spelling AloudA2 — Spoken German says the units before the tens (einundzwanzig = 'one-and-twenty'), uses zwo on the phone to avoid confusion with drei, and has its own spelling alphabet — the survival skills for phone numbers, prices, dates, and dictation.
- Ordinal NumbersA2 — Forming German ordinals with -t (1-19) and -st (from 20), the irregulars erste, dritte, siebte and achte, why ordinals take adjective endings (am zweiten Mai), and the period-as-ordinal-marker (1. = erste).
- Dialogue: Shopping and PricesA2 — An annotated A2 market dialogue covering quantity plus singular unit (zwei Kilo Äpfel), Haben Sie...?, Ich nehme..., reading a decimal-comma price, and the paying phrases bar oder mit Karte and Stimmt so.