Ordinal Numbers in English

Overview

Ordinal numbers describe the position or order of something in a sequence: first, second, third, fourth, and so on. They are used for dates, floors of buildings, rankings, centuries, and any situation where order matters.

At the A1 (Beginner) level, ordinal numbers are essential for telling dates ("May 5th"), describing where things are ("the third door on the left"), and talking about sequences ("my first day at work"). They appear constantly in everyday English.

The first three ordinal numbers (first, second, third) are irregular and must be memorized. After that, the pattern is simple: add -th to the cardinal number, with a few spelling adjustments.

How It Works

Ordinal numbers 1st-12th

Cardinal	Ordinal	Abbreviation
one	first	1st
two	second	2nd
three	third	3rd
four	fourth	4th
five	fifth	5th
six	sixth	6th
seven	seventh	7th
eight	eighth	8th
nine	ninth	9th
ten	tenth	10th
eleven	eleventh	11th
twelve	twelfth	12th

Irregular spelling to note

• fifth (not "fiveth") -- "ve" changes to "f"
• eighth (not "eightth") -- only one "t"
• ninth (not "nineth") -- the "e" is dropped
• twelfth (not "twelveth") -- "ve" changes to "f"

Ordinal numbers 13th-19th

Simply add -th: thirteenth, fourteenth, fifteenth, sixteenth, seventeenth, eighteenth, nineteenth.

Tens

Drop the "y" and add -ieth: twentieth (20th), thirtieth (30th), fortieth (40th), fiftieth (50th).

Compound ordinals

Only the last number becomes ordinal:

• 21st = twenty-first
• 32nd = thirty-second
• 43rd = forty-third
• 55th = fifty-fifth
• 100th = one hundredth

Using ordinals

Ordinals are usually preceded by "the":

• the first day, the second floor, the third time

Examples in Context

English	Note
The first day of school	Position in a sequence
The second floor	Floor of a building
May 5th (May fifth)	Date -- ordinal for the day
She came third.	Ranking -- no "the" needed here
It's my twenty-first birthday.	Compound ordinal
He lives on the fourth street.	Location
This is the tenth time I've called.	Counting occurrences
The third door on the left.	Giving directions
Happy 1st anniversary!	Written abbreviation
She finished in second place.	Competition ranking

Common Mistakes

Spelling "fifth" and "ninth" incorrectly

• Wrong: fiveth, nineth
• Right: fifth, ninth
• Why: These are irregular spellings. "Five" changes to "fif-" and "nine" drops the "e" before adding "-th."

Making the wrong part ordinal in compound numbers

• Wrong: the twentieth-one, the thirtieth-two
• Right: the twenty-first, the thirty-second
• Why: In compound ordinals, only the last number becomes ordinal. The first part stays as a cardinal number.

Forgetting "the" before ordinals

• Wrong: I live on third floor.
• Right: I live on the third floor.
• Why: Ordinal numbers are typically preceded by "the" (or a possessive adjective like "my"). Exceptions include some fixed expressions and rankings after verbs.

Using cardinal numbers for dates in speech

• Wrong: Saying "May five" for a date
• Right: Saying "May fifth" or "the fifth of May"
• Why: In spoken English, dates use ordinal numbers. Even when written as "May 5," it is spoken as "May fifth."

Usage Notes

Date formats differ between British and American English:

Format	British English	American English
Written	5th May / 5 May	May 5th / May 5
Spoken	the fifth of May	May fifth

Both formats are widely understood, but be consistent within your writing.

Abbreviations (1st, 2nd, 3rd, 4th) are common in informal writing. In formal writing, spell out ordinal numbers, especially for small numbers: "the third chapter" rather than "the 3rd chapter."

Floor numbering differs too: in British English, the "ground floor" is the entry level, and the "first floor" is one level up. In American English, the "first floor" is the entry level.

Practice Tips

• Practice dates: Say today's date and the dates of birthdays you know using ordinal numbers. "Today is the first of April. My birthday is on the twenty-third of June."
• Memorize the irregulars: Focus on first, second, third, fifth, eighth, ninth, and twelfth. These are the ones that trip people up.
• Floor counting: Next time you are in a building, count the floors using ordinals: "ground floor, first floor, second floor..." (or "first floor, second floor..." in American counting).

Related Concepts

• Prerequisite: Cardinal Numbers -- you need to know cardinal numbers before forming ordinals