Cardinal Numbers in English

Overview

Cardinal numbers are the counting numbers: one, two, three, and so on. They are used for counting, giving quantities, telling your age, giving phone numbers, and much more. At the A1 (Beginner) level, you need to know numbers from 0 to at least 100.

Learning numbers in English is fairly straightforward because the system is regular once you understand the patterns. The numbers 1-12 each have unique names that must be memorized, but from 13 onward, clear patterns emerge.

Numbers are one of the first things you need in practical situations: shopping, exchanging phone numbers, discussing times, talking about prices, and giving your address.

How It Works

Numbers 0-12 (memorize these)

Number	Word	Number	Word
0	zero	7	seven
1	one	8	eight
2	two	9	nine
3	three	10	ten
4	four	11	eleven
5	five	12	twelve
6	six

Numbers 13-19 (the "-teen" numbers)

Number	Word	Note
13	thirteen	thir- (not "three-teen")
14	fourteen	regular
15	fifteen	fif- (not "five-teen")
16	sixteen	regular
17	seventeen	regular
18	eighteen	only one "t" (not "eight-teen")
19	nineteen	regular

Tens (20-90)

Number	Word	Number	Word
20	twenty	60	sixty
30	thirty	70	seventy
40	forty	80	eighty
50	fifty	90	ninety

Note: "Forty" has no "u" -- it is NOT "fourty."

Compound numbers (21-99)

Use a hyphen between the tens and ones: twenty-one, thirty-five, forty-eight, ninety-nine.

100 and beyond

Number	Word
100	one hundred / a hundred
101	one hundred and one (BrE) / one hundred one (AmE)
200	two hundred
1,000	one thousand / a thousand

Note: "Hundred" and "thousand" do not add -s when preceded by a number: two hundred (not "two hundreds").

Zero

English has several words for 0:

Word	Context
zero	General, temperatures, mathematics
oh / O	Phone numbers, room numbers, years
nil	Sports scores (BrE)
nothing	Informal

Examples in Context

English	Note
one, two, three	Basic counting
twenty-one	Hyphen in compound numbers
one hundred	Using "one" before "hundred"
fifty-five	Compound number
My phone number is 07700 900 461.	Say each digit: "oh-seven-seven-oh-oh..."
I'm thirty-two years old.	Age
That costs ninety-nine pounds.	Price
There are twelve months in a year.	Quantity
The temperature is zero degrees.	Temperature
She lives at number forty-eight.	Address

Common Mistakes

Spelling "forty" with a "u"

• Wrong: fourty
• Right: forty
• Why: Despite "four" having a "u," the word "forty" drops it. This is one of the most common spelling errors in English.

Adding -s to hundred/thousand after numbers

• Wrong: three hundreds, five thousands
• Right: three hundred, five thousand
• Why: When a specific number comes before "hundred" or "thousand," they do not take -s. However, you can say "hundreds of people" or "thousands of years" when the number is vague.

Confusing "-teen" and "-ty"

• Wrong: Saying "thirty" when you mean "thirteen" (or vice versa)
• Right: Practice the stress difference: thirTEEN vs. THIRty
• Why: The "-teen" numbers are stressed on the second syllable, while the "-ty" numbers are stressed on the first. This distinction is crucial for being understood.

Usage Notes

British English uses "and" after "hundred" in numbers: "one hundred and one" (101). American English often omits it: "one hundred one." Both are correct.

For phone numbers, say each digit separately. Zero is usually said as "oh": 0207 becomes "oh-two-oh-seven." In American English, zero is sometimes said as "zero" in phone numbers.

When writing numbers in text, a common guideline is to spell out numbers one through nine and use digits for 10 and above. However, this varies by style guide.

Practice Tips

• Count regularly: Practice counting from 1 to 100 out loud. Focus on the transition points (12 to 13, 19 to 20, 29 to 30, etc.).
• Practice phone numbers: Write down phone numbers and practice saying them aloud digit by digit.
• Stress drills: Practice pairs like thirteen/thirty, fourteen/forty, fifteen/fifty to master the stress difference between "-teen" and "-ty" numbers.

Related Concepts

• Next steps: Ordinal Numbers -- the "first, second, third" forms used for dates and rankings
• Next steps: Telling Time -- using numbers to express time