Cardinal Numbers in Italian

Overview

Italian cardinal numbers from 0 to 100 follow a logical and largely predictable pattern. Once you learn the numbers 0–20 and the tens (30, 40, 50…), you can build any number up to 100 by combining them — much like English, but written as a single word.

The main quirk to watch for is the number uno (one), which changes form depending on the gender of the noun it accompanies: un before most masculine nouns and una before feminine nouns. You will also notice a small spelling rule when combining tens with uno or otto: the final vowel of the ten is dropped to keep pronunciation smooth (ventuno, ventotto).

Numbers are among the first things you use every day — telling your age, asking for prices, giving your phone number, ordering at a restaurant. Mastering 0–100 gives you a solid foundation for Time & Dates and Ordinal Numbers.

How It Works

Numbers 0–20

These must be memorized individually, as several are irregular.

Number	Italian	Number	Italian
0	zero	11	undici
1	uno	12	dodici
2	due	13	tredici
3	tre	14	quattordici
4	quattro	15	quindici
5	cinque	16	sedici
6	sei	17	diciassette
7	sette	18	diciotto
8	otto	19	diciannove
9	nove	20	venti
10	dieci

The Tens (20–100)

Number	Italian
20	venti
30	trenta
40	quaranta
50	cinquanta
60	sessanta
70	settanta
80	ottanta
90	novanta
100	cento

Combining Tens and Units

To form numbers like 21, 35, or 99, attach the unit directly to the ten as one word:

• 21 → venti + uno → ventuno
• 35 → trenta + cinque → trentacinque
• 99 → novanta + nove → novantanove

Drop-the-vowel rule: When the unit is uno (1) or otto (8), the final vowel of the ten drops:

Pattern	Example	Result
venti + uno	ventuno	ventuno (21)
trenta + uno	trentuno	trentuno (31)
quaranta + otto	quarantotto	quarantotto (48)
sessanta + otto	sessantotto	sessantotto (68)

For all other units (2–7, 9), just attach them directly — no letter changes:

Example	Result
venti + due	ventidue (22)
trenta + tre	trentatré (33)
cinquanta + quattro	cinquantaquattro (54)

Note that trentatré (33) carries an accent on the final e, just as tre does when it is the last syllable of a compound number.

Gender of "uno"

When uno is used before a noun, it behaves like an indefinite article and agrees in gender:

Context	Form	Example
Before masculine noun	un	un libro (one book)
Before feminine noun	una	una casa (one house)
Counting or standalone	uno	uno, due, tre…

This gender agreement also applies in compound numbers: ventun anni (twenty-one years, masculine), ventun'ore or ventuna ore (twenty-one hours, feminine).

Examples in Context

Italian	English	Note
Ho venticinque anni.	I am twenty-five years old.	Age uses avere (to have)
Quanto costa? — Tre euro.	How much does it cost? — Three euros.	Prices in everyday shopping
Siamo in quattro.	There are four of us.	Counting people
Il treno parte alle diciotto.	The train leaves at eighteen (6 PM).	24-hour clock common in Italy
Abito al numero quarantadue.	I live at number forty-two.	Street addresses
Ci sono trenta studenti in classe.	There are thirty students in the class.	Classroom context
Ha cinquantuno anni.	He/She is fifty-one years old.	Vowel drop: cinquantuno
Costa ventotto euro.	It costs twenty-eight euros.	Vowel drop: ventotto
Vorrei due caffè, per favore.	I would like two coffees, please.	Ordering at a bar
La risposta è cento.	The answer is one hundred.	Cento never changes form
Ho solo un euro.	I have only one euro.	un before masculine noun
C'è una pizza per te.	There is one pizza for you.	una before feminine noun

Common Mistakes

Writing two separate words

• Wrong: venti uno, trenta cinque
• Right: ventuno, trentacinque
• Why: Italian compound numbers from 21 to 99 are always written as a single word, never two.

Forgetting to drop the vowel before uno/otto

• Wrong: ventiuno, ventiotto
• Right: ventuno, ventotto
• Why: When a ten (venti, trenta, etc.) combines with uno or otto, the final vowel of the ten is dropped for smoother pronunciation.

Using "uno" before a noun instead of "un/una"

• Wrong: uno libro, uno casa
• Right: un libro, una casa
• Why: Before a noun, uno shortens to un (masculine) or una (feminine), following the same rules as the indefinite article.

Forgetting the accent on trentatré

• Wrong: trentatre
• Right: trentatré
• Why: The word tre carries a written accent when it appears at the end of a compound number (trentatré, quarantatré, etc.).

Saying "cento uno" instead of "centouno"

• Wrong: cento uno
• Right: centouno (101)
• Why: Just like the tens, cento joins directly with the following number as a single word.

Practice Tips

1. Count out loud daily. Pick a routine activity — climbing stairs, walking, doing exercises — and count each step in Italian. Start with 1–20, then expand to 100. Hearing yourself say the numbers builds fluency faster than reading alone.

2. Play the price game. When you see prices in a shop or online, say them in Italian. A shirt for €48? Quarantotto euro. A book for €21? Ventuno euro. This connects numbers to real-life contexts and reinforces the vowel-drop rule naturally.

3. Write numbers as words. When texting or making notes, write Italian numbers as words instead of digits for a week. This drills spelling and helps you internalize compound forms like sessantasei or novantanove.

Related Concepts

• Next step: Ordinal Numbers — primo, secondo, terzo… built on top of cardinal numbers
• Next step: Time & Dates — telling time and reading dates requires solid number knowledge