Ordinal numbers show position or order: the first day, the third floor, my second language. They are also used for dates, floors of a building and centuries. Most ordinals are made by adding -th to the cardinal number, but a few are irregular.
Ordinal numbers 1st–31st
| Written | Word |
|---|---|
| 1st | first |
| 2nd | second |
| 3rd | third |
| 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 |
| 21st | twenty-first |
| 22nd | twenty-second |
| 23rd | twenty-third |
| 24th | twenty-fourth |
| 25th | twenty-fifth |
| 26th | twenty-sixth |
| 27th | twenty-seventh |
| 28th | twenty-eighth |
| 29th | twenty-ninth |
| 30th | thirtieth |
| 31st | thirty-first |
Bigger ordinals
| Written | Word |
|---|---|
| 40th | fortieth |
| 50th | fiftieth |
| 60th | sixtieth |
| 70th | seventieth |
| 80th | eightieth |
| 90th | ninetieth |
| 100th | one hundredth |
| 1000th | one thousandth |
Spelling rules
- Irregular: one → first, two → second, three → third.
- Changed spelling: five → fifth, eight → eighth, nine → ninth, twelve → twelfth.
- Tens ending in -y: y → -ieth: twenty → twentieth, thirty → thirtieth.
- Compound numbers: only the last part changes: twenty-first, one hundred and fifth.
- Abbreviations: 1st, 2nd, 3rd, 4th… 11th, 12th, 13th (always -th), 21st, 22nd, 23rd.
Dates
We use ordinals for the day of the month. In British English: the 5th of May (written 5 May or 5th May). In American English: May 5th (said “May fifth”). Years are cardinal: the 5th of May, 2026 is “the fifth of May, twenty twenty-six”.
| Written | British English | American English |
|---|---|---|
| 3 March | the third of March | March third |
| 22 November | the twenty-second of November | November twenty-second |
| 1 January 2027 | the first of January, twenty twenty-seven | January first, twenty twenty-seven |
Other uses of ordinals
- Floors: the ground floor (UK) / first floor (US) and the second floor.
- Centuries: the 21st century – “the twenty-first century”.
- Order in a series: Henry the Eighth, the third time, on the fourth try.
- Fractions: a third (1/3), a fifth (1/5), three quarters (3/4).
Common mistakes
- the twentyth → the twentieth; nineth → ninth; twelveth → twelfth.
- Forgetting the before an ordinal: I live on third floor → I live on the third floor.
- May the 5 → May 5th or the 5th of May.
Frequently asked questions
Do we say “the” before ordinals?
Usually yes: the first, the second. Without “the” we use them as adverbs: “First, open the box. Second, remove the cover.”
What is the difference between “the first floor” in the UK and US?
In British English the first floor is above the ground floor. In American English the first floor is the ground floor.