- Understand the difference between cardinal (uno, dos, tres) and ordinal (primero, segundo, tercero) numbers
- Master agreement rules for ordinal numbers (primero/primera, tercero/tercera)
- Learn apocope: when primero becomes primer and tercero becomes tercer
- Know when to use cardinals vs ordinals in dates, rankings, floors, and kings
- Form complex numbers like 222 (doscientos veintidós) and understand why complex ordinals are rarely used
- Avoid common mistakes like using ordinals for dates (except el primero)
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Cardinal and ordinal numbers
What You'll Learn
Overview / Usage
Cardinal vs ordinal numbers
Cardinal numbers
What they are: Counting numbers
Examples: uno, dos, tres, cuatro...
Used for: Quantities, ages, phone numbers, most dates
Tengo dos hermanos
I have two siblings
Ordinal numbers
What they are: Ordering/ranking numbers
Examples: primero, segundo, tercero, cuarto...
Used for: Floors, rankings, kings, centuries
Vivo en el tercer piso
I live on the third floor
Structure & Formation
Cardinal numbers (1-1000+)
Basic cardinals (1-19)
1 - uno
2 - dos
3 - tres
4 - cuatro
5 - cinco
6 - seis
7 - siete
8 - ocho
9 - nueve
10 - diez
11 - once
12 - doce
13 - trece
14 - catorce
15 - quince
16 - dieciséis
17 - diecisiete
18 - dieciocho
19 - diecinueve
💡 Agreement with "uno"
Uno changes to un before masculine nouns and una before feminine nouns:
un libro (one book)
masculine
una casa (one house)
feminine
This applies to 21, 31, 41... (veintiún, treinta y un, cuarenta y una, etc.)
Tens (20-90)
20 - veinte
21 - veintiuno
22 - veintidós
23 - veintitrés
30 - treinta
40 - cuarenta
50 - cincuenta
60 - sesenta
70 - setenta
80 - ochenta
90 - noventa
Note: 21-29 use "veinti-" (veintidós, veintitrés), but 31+ use "y" (treinta y uno, cuarenta y dos)
Hundreds agreement
200-900 agree in gender with the noun they modify:
doscientos libros
200 books (masculine)
doscientas páginas
200 pages (feminine)
That's why you'll see -os/as notation in the hundreds list below
Hundreds (100-900)
100 - cien / ciento
200 - doscientos/as
300 - trescientos/as
400 - cuatrocientos/as
500 - quinientos/as
600 - seiscientos/as
700 - setecientos/as
800 - ochocientos/as
900 - novecientos/as
Cien vs ciento
CIEN (exactly 100)
cien personas
100 people
cien mil
100,000
CIENTO (101-199)
ciento cinco euros
105 euros
ciento veinte
120
Complex numbers (like 222, 1,567)
Pattern: [hundreds] + [tens] + [y] + [units]
222
doscientos veintidós
No "y" between hundreds and tens
345
trescientos cuarenta y cinco
"y" only between tens and units
1,567
mil quinientos sesenta y siete
"mil" doesn't change form
2,000,000
dos millones
"millón" becomes "millones" (plural)
Thousands, millions, and billions
Large numbers
1,000 - mil
2,000 - dos mil
10,000 - diez mil
100,000 - cien mil
1,000,000 - un millón
2,000,000 - dos millones
1,000,000,000 - mil millones
1,000,000,000,000 - un billón
⚠️ Important notes:
- mil never changes form (always "mil", never "miles" for quantity)
- un millón and un billón DO use "un" (unlike "mil")
- millón/millones requires "de" before a noun: un millón de personas
- billón = trillion in US English (1,000,000,000,000), not billion!
Large number examples
5,432
cinco mil cuatrocientos treinta y dos
Five thousand, four hundred thirty-two
1,250,000
un millón doscientos cincuenta mil
One million, two hundred fifty thousand
7.5 billion
siete mil quinientos millones
7,500,000,000 (seven thousand five hundred million)
With noun
tres millones de habitantes
3,000,000 inhabitants (note: "de" required)
Ordinal numbers (1st-10th and beyond)
Common ordinals (1st-10th)
These are used frequently in everyday Spanish:
1st - primero/a
2nd - segundo/a
3rd - tercero/a
4th - cuarto/a
5th - quinto/a
6th - sexto/a
7th - séptimo/a
8th - octavo/a
9th - noveno/a
10th - décimo/a
💡 Ordinals beyond 10th
While ordinals exist for all numbers (11th = undécimo, 20th = vigésimo, 100th = centésimo, 222nd = ducentésimo vigésimo segundo), they are rarely used in everyday speech beyond 10th.
What native speakers do:
mi cumpleaños número treinta
my 30th birthday (using cardinal)
el piso veintiuno
the 21st floor (using cardinal)
Exception: Formal writing, legal documents, and some fixed expressions may use complex ordinals.
For reference: 11th-20th (rarely spoken)
11th - undécimo/a or decimoprimero/a
12th - duodécimo/a or decimosegundo/a
13th - decimotercero/a
14th - decimocuarto/a
15th - decimoquinto/a
16th - decimosexto/a
17th - decimoséptimo/a
18th - decimoctavo/a
19th - decimonoveno/a
20th - vigésimo/a
You'll see these in writing (especially legal/formal texts) but almost never hear them in conversation. Note: 11th and 12th have two forms each - both are correct!
For reference: 100th-1000th (formal/written Spanish only)
These exist but are extremely rare in spoken Spanish. You'll only see them in very formal or legal writing:
30th - trigésimo/a
40th - cuadragésimo/a
50th - quincuagésimo/a
60th - sexagésimo/a
70th - septuagésimo/a
80th - octogésimo/a
90th - nonagésimo/a
100th - centésimo/a
200th - ducentésimo/a
300th - tricentésimo/a
500th - quingentésimo/a
1000th - milésimo/a
Complex ordinal examples (for reference only)
While these technically exist, native speakers almost never use them in speech:
21st
vigésimo primero/a
Formal writing only
el número veintiuno
What people actually say
100th
centésimo/a
Written: el centésimo aniversario
el aniversario número cien
What people say
123rd
centésimo vigésimo tercero/a
Exists in theory!
el número ciento veintitrés
What everyone actually uses
222nd
ducentésimo vigésimo segundo/a
Only in very formal documents
el puesto doscientos veintidós
Normal speech
1000th
milésimo/a
el milésimo visitante (formal)
el visitante número mil
Common usage
💡 Takeaway: In everyday Spanish, use cardinal numbers for rankings and positions beyond 10th. Save ordinals for very formal writing or when you want to sound extra fancy!
Ordinal agreement
Ordinals agree in gender and number
Ordinals are adjectives, so they must agree with the noun:
Masculine singular
el primer día
the first day
Feminine singular
la primera vez
the first time
Masculine plural
los primeros años
the first years
Feminine plural
las primeras semanas
the first weeks
Apocope: primero → primer, tercero → tercer
When to drop the -o
Primero and tercero lose the final -o before masculine singular nouns only:
Before masculine singular noun
el primer lugar
the first place
el tercer piso
the third floor
All other cases keep -o
la primera casa
the first house (feminine)
Es el primero
He's the first one (no noun after)
When to use cardinals vs ordinals
Dates - use CARDINALS (except 1st)
el cinco de mayo
the 5th of May
el primero de enero
the 1st of January (exception!)
Floors - use ORDINALS (1st-10th)
Vivo en el cuarto piso
I live on the 4th floor
la planta baja
ground floor (special term)
Kings/Queens/Popes - use ORDINALS
Felipe Sexto
King Felipe VI
Isabel Segunda
Queen Elizabeth II
Centuries - BOTH accepted
el siglo veintiuno
21st century (cardinal, more common)
el siglo vigésimo primero
21st century (ordinal, formal)
Ages - use CARDINALS
Tengo treinta años
I'm 30 years old
Cumplo cuarenta mañana
I turn 40 tomorrow
Rankings/Positions - ORDINALS (1st-10th)
Quedé en segundo lugar
I came in second place
la quinta avenida
Fifth Avenue
Examples
Shopping & prices
Cuesta doscientos cincuenta euros
It costs 250 euros
Son treinta y dos con cincuenta
That's 32.50
Dates
Nací el veinticinco de diciembre
I was born on the 25th of December
Hoy es el primero de enero
Today is the 1st of January
Buildings & floors
Vivo en el tercer piso
I live on the 3rd floor
La oficina está en la quinta planta
The office is on the 5th floor
Rankings & positions
Quedó en primer lugar
He/she came in first place
Soy el número quince en la lista
I'm number 15 on the list
Ages & quantities
Tengo treinta y cinco años
I'm 35 years old
Hay cincuenta estudiantes en la clase
There are 50 students in the class
Large numbers
La ciudad tiene dos millones de habitantes
The city has 2 million inhabitants
Ganó quinientos mil dólares
He/she won 500,000 dollars
Gotchas / Common Mistakes
Quick Test / Mini Quiz
1
What's the correct way to say 'the first house'?
2
How do you say '21st of March' in Spanish?
3
Which is correct for 'King Charles III'?
4
Complete: 'Vivo en el ___ piso' (I live on the 3rd floor)
5
How do you say '222' in Spanish?
6
What's correct for 'the first day'?
7
For 'my 30th birthday', would you use ordinals?
8
Which is correct: 'the 21st century'?
Useful Resources
Coming soon...