November 13, 2024

[Aroline Hanson, Ph.D.](https://blog.duolingo.com/author/aroline/)

# How to form numbers in English, from 1 to a billion

Learning these patterns will help you remember the numbers in English!

When you are learning a new language, there seem to be _innumerable_ words! But you can _count_ on us to help. One set of important words in English is vocabulary for numbers. Here are the basics!

## Numbers from 1-10 in English

The number one tip for learning the numbers is that you should start small. Here are the words for the numbers 1 through 10.

| Digit | English |
| --- | --- |
| 1 | one |
| 2 | two |
| 3 | three |
| 4 | four |
| 5 | five |
| 6 | six |
| 7 | seven |
| 8 | eight |
| 9 | nine |
| 10 | ten |

The number words in English do not change with different nouns. For example, you can say I have two pizzas and I have two children. However, if you only have one of something, you might not say one unless you want it to be clear that you have just one. Instead of _I have **one** pizza_, you’ll more often say I have a pizza. If the noun begins with a [vowel](https://blog.duolingo.com/english-alphabet-pronunciation/), you’ll use the form an: I have an eggplant.

## Numbers from 10-20 in English

Once you get past 10 in English, there are the slightly odd numbers [11 and 12](https://blog.duolingo.com/words-for-eleven-twelve/). The word _eleven_ originally meant “one left over (from ten)” in [Old English](https://blog.duolingo.com/history-of-english-language/) and _twelve_ meant “two left over.”

After the word _twelve_, English numbers have a rather transparent pattern: quantity above 10 + _-teen_. For example, 16 is _sixteen_, or _six_ \+ _-teen_(6+10). Notice that the words for 13 and 15 are slightly different from what you’d expect from the pattern—these number [words have changed a bit over time](https://blog.duolingo.com/why-do-languages-change/)!

| Digit | English |
| --- | --- |
| 10 | ten |
| 11 | eleven |
| 12 | twelve |
| 13 | thirteen |
| 14 | fourteen |
| 15 | fifteen |
| 16 | sixteen |
| 17 | seventeen |
| 18 | eighteen |
| 19 | nineteen |
| 20 | twenty |

In English, if you are 20 years old, you would say I am twenty. If you are older than 12 but younger than 20, you are considered to be a teenager or in your teens.

## Numbers from 20-100 in English

For the numbers higher than 20, there are more patterns to look for. For the tens words (30, 40, 50, etc), the English words have the ending _-ty_ (as in _thir **ty**_ for 30 and _for **ty**_ for 40). The other numbers above 20 are compound words: _twenty-one_ for 21 (20+1), _twenty-two_ for 22 (20+2), _twenty-three_ for 23 (20+3), etc.

| Digit | English |
| --- | --- |
| 10 | ten |
| 20 | twenty |
| 21 | twenty-one |
| 22 | twenty-two |
| 23 | twenty-three |
| 30 | thirty |
| 31 | thirty-one |
| 40 | forty |
| 41 | forty-one |
| 50 | fifty |
| 51 | fifty-one |
| 60 | sixty |
| 70 | seventy |
| 80 | eighty |
| 90 | ninety |
| 100 | one hundred / a hundred |

Just as with _one_ of something, when you have 100 of an item, you can say a hundred instead of one hundred. The use of _one hundred_ is more precise, while _a hundred_ is somewhat vague. For example, I have a hundred emails to respond to may mean that you simply have [a lot](https://blog.duolingo.com/synonyms-for-a-lot/) of emails in your inbox.

## Numbers from 100 to 1000 in English

For numbers above 100, English sometimes uses the word and to join them, as in one hundred and one Dalmatians for the number 101.

As with 1 and 100, you can say one thousand or a thousand for 1,000. When you use _one thousand_, you are indicating a precise quantity.

| Digit | English |
| --- | --- |
| 100 | one hundred / a hundred |
| 101 | one hundred one / one hundred and one |
| 200 | two hundred |
| 300 | three hundred |
| 400 | four hundred |
| 500 | five hundred |
| 600 | six hundred |
| 700 | seven hundred |
| 800 | eight hundred |
| 900 | nine hundred |
| 1,000 | one thousand / a thousand |

## Numbers from 1,000 to 1,000,000

In English, a comma is placed after the thousands numeral, while many other languages use a period. For example, in English you write There are 22,500 students at the university. If a number is only four digits long, the comma is not required, but it is used sometimes for clarity.

Here are the English words for 1,000 to 1,000,000:

| Digit | English |
| --- | --- |
| 1,000 | one thousand / a thousand |
| 1,001 | one thousand and one / a thousand and one |
| 1,100 | one thousand, one hundred / eleven hundred |
| 1,150 | one thousand, one hundred and fifty / eleven hundred and fifty / eleven fifty |
| 2,000 | two thousand |
| 3,000 | three thousand |
| 10,000 | ten thousand |
| 10,100 | ten thousand, one hundred |
| 10,150 | ten thousand, one hundred and fifty |
| 20,000 | twenty thousand |
| 30,000 | thirty thousand |
| 100,000 | one hundred thousand / a hundred thousand |
| 101,000 | one hundred and one thousand |
| 101,100 | one hundred and one thousand, one hundred |
| 200,000 | two hundred thousand |
| 300,000 | three hundred thousand |
| 1,000,000 | one million / a million |
| 1,100,000 | one million, one hundred thousand / one point one million |

## More numbers in English

For really large numbers, you might encounter some differences depending on the [dialect of English](https://blog.duolingo.com/english-dialects/)! For the number with nine zeros—1,000,000,000—you’ll hear billion in U.S. English but a thousand million in British English. In U.S. English, the number with 12 zeros is a trillion but is called a billion in the U.K.… which, of course, can lead to confusion! Unless you are a scientist or a mathematician, you may just want to use [a synonym for _a lot_](https://blog.duolingo.com/synonyms-for-a-lot/) for these quantities.

## Ordinal numbers in English

In addition to these _cardinal_ numbers, you’ll also need _ordinal_ numbers. Ordinal numbers are the way of referring to numbers in a particular sequence or order—for example, first place or eighteenth century.

Most ordinal numbers in English have the ending _-th_, but there are a few other patterns to know.

- **Numbers ending in 1:** Any number that ends in _one_ uses the word _first_ for the ordinal number. This comes from the Old English word meaning “foremost.” You’ll see these numbers abbreviated with the ending _-st_, like _1st, 21st,_ and _431st_. Note that if the number ends in _eleven_, you’ll instead use _-th_: _11th, 111th, 3,711th,_ etc.
- **Numbers ending in 2:** Any number that ends in _two_ uses the word _second_ for the ordinal number, from the Latin word meaning “following.” These are abbreviated with the digit and the ending _-nd_. Here also, there is an exception: You’ll use _-th_ for numbers ending in _twelve_: _12th, 112th, 812th,_ etc.
- **Numbers ending in 3:** Any number that ends in _three_ uses the word _third_ for the ordinal number. These numbers are abbreviated with the digit and the ending _-rd_. Again, _thirteen_ will be an exception that uses _-th_: _13th, 113th, 513th,_ etc.

| Ordinal ending | Digit | English |
| --- | --- | --- |
| -st | 1st | first |
| 21st | twenty-first |
| -nd | 2nd | second |
| 22nd | twenty-second |
| -rd | 3rd | third |
| 23rd | twenty-third |
| -th | 4th | fourth |
| 5th | fifth |
| 6th | sixth |
| 7th | seventh |
| 8th | eighth |
| 9th | ninth |
| 10th | tenth |
| 11th | eleventh |
| 12th | twelfth |
| 13th | thirteenth |
| 14th | fourteenth |
| 15th | fifteenth |
| 16th | sixteenth |
| 17th | seventeenth |
| 18th | eighteenth |
| 19th | nineteenth |
| 20th | twentieth |
| 24th | twenty-fourth |
| 25th | twenty-fifth |

## Overview of numbers in English

Here’s an overview of the most important number words in English.

| Digit | English cardinal number | English ordinal number |
| --- | --- | --- |
| 1 | one | first (1st) |
| 2 | two | second (2nd) |
| 3 | three | third (3rd) |
| 4 | four | fourth (4th) |
| 5 | five | fifth (5th) |
| 6 | six | sixth (6th) |
| 7 | seven | seventh (7th) |
| 8 | eight | eighth (8th) |
| 9 | nine | ninth (9th) |
| 10 | ten | tenth (10th) |
| 11 | eleven | eleventh (11th) |
| 12 | twelve | twelfth (12th) |
| 13 | thirteen | thirteenth (13th) |
| 14 | fourteen | fourteenth (14th) |
| 15 | fifteen | fifteenth (15th) |
| 16 | sixteen | sixteenth (16th) |
| 17 | seventeen | seventeenth (17th) |
| 18 | eighteen | eighteenth (18th) |
| 19 | nineteen | nineteenth (19th) |
| 20 | twenty | twentieth (20th) |
| 21 | twenty-one | twenty-first (21st) |
| 22 | twenty-two | twenty-second (22nd) |
| 23 | twenty-three | twenty-third (23rd) |
| 24 | twenty-four | twenty-fourth (24th) |
| 30 | thirty | thirtieth (30th) |
| 40 | forty | fortieth (40th) |
| 50 | fifty | fiftieth (50th) |
| 60 | sixty | sixtieth (60th) |
| 70 | seventy | seventieth (70th) |
| 80 | eighty | eightieth (80th) |
| 90 | ninety | ninetieth (90th) |
| 100 | one hundred / a hundred | (one) hundredth (100th) |
| 101 | one hundred one / one hundred and one | (one) hundred and first (101st) |
| 200 | two hundred | two hundredth (200th) |
| 300 | three hundred | three hundredth (300th) |
| 327 | three hundred twenty- seven / three hundred and twenty-seven | three hundred and twenty-seventh (327th) |
| 400 | four hundred | four hundredth (400th) |
| 500 | five hundred | five hundredth (500th) |
| 600 | six hundred | six hundredth (600th) |
| 700 | seven hundred | seven hundredth (700th) |
| 800 | eight hundred | eight hundredth (800th) |
| 900 | nine hundred | nine hundredth (900th) |
| 1,000 | one thousand / a thousand | one thousandth (1000th) |
| 4,580 | four thousand, five hundred eighty / four thousand, five hundred and eighty | four thousand, five hundred and eightieth (4580th) |
| 10,000 | ten thousand | ten thousandth (10,000th) |
| 14,642 | fourteen thousand, six hundred forty-two / fourteen thousand, six hundred and forty-two | fourteen thousand, six hundred and forty-second (14,642nd) |
| 100,000 | one hundred thousand / a hundred thousand | (one) hundred thousandth (100,000th) |
| 930,021 | nine hundred thirty thousand twenty-one / nine hundred thirty thousand and twenty-one | nine hundred thirty thousand and twenty-first (930,021st) |
| 1,000,000 | one million / a million | one millionth (1,000,000th) |

Now you have about _a_ _hundred_ new words for the numbers in English. So for the _millionth_ time, go study!