Ordinal Numbers in English

In Brief

Ordinal numbers show a position in an order: first, second, third, fourth. The first three forms are irregular; most others are made with -th, with a few spelling changes such as fifth, eighth, ninth, and twelfth. In figures, they are written 1st, 2nd, 3rd, 4th, and only the final part of a compound number becomes ordinal: twenty-first (21st).

Overview

An ordinal number tells you the position of someone or something in a sequence. It answers a question such as “Which one in the order?” In the third chapter, for example, third identifies the chapter’s position. A cardinal number (an ordinary counting number) answers “How many?”: three chapters.

This is an A1 topic because ordinals appear in many everyday situations. You use them for dates (May fifth), rankings (She finished second), directions (Take the first right), repeated events (my third visit), and numbered parts of buildings or texts (the fourth floor, the second paragraph).

The beginner pattern is manageable: learn first, second, and third separately, use -th for most later numbers, and memorize a small group of spelling exceptions. The later sections explain useful details about articles, dates, large numbers, floors, fractions, and formal names.

How It Works

Cardinal and ordinal numbers

Cardinal: quantity	Ordinal: position	Figure
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

The ending -th is regular in fourth, sixth, seventh, tenth, and eleventh. Notice these important spellings:

• five → fifth: ve changes to f.
• eight → eighth: there is only one t.
• nine → ninth: the final e disappears.
• twelve → twelfth: ve changes to f.

For the teens, add -th to the cardinal form: thirteenth, fourteenth, fifteenth, sixteenth, seventeenth, eighteenth, and nineteenth. Fifteenth follows the spelling of fifth.

Tens and compound numbers

Whole tens ending in -y change y to ie before -th.

Cardinal	Ordinal	Figure
twenty	twentieth	20th
thirty	thirtieth	30th
forty	fortieth	40th
fifty	fiftieth	50th
eighty	eightieth	80th
ninety	ninetieth	90th

In a compound number, only the final element takes the ordinal form. Keep the normal hyphen used in numbers from twenty-one to ninety-nine.

Cardinal	Ordinal	Figure
twenty-one	twenty-first	21st
thirty-two	thirty-second	32nd
forty-three	forty-third	43rd
fifty-four	fifty-fourth	54th
ninety-nine	ninety-ninth	99th

The same principle continues with larger numbers: one hundred and first (101st in British usage, also one hundred first in American usage), two hundredth (200th), and one thousandth (1,000th). When the number ends in an exact hundred or thousand, that final unit becomes ordinal. When more digits follow, only the final spoken element is ordinal.

Choosing the written suffix

Use -st after numbers ending in 1, -nd after numbers ending in 2, and -rd after numbers ending in 3. Use -th for the others. However, 11, 12, and 13 are exceptions, even inside larger numbers:

• 1st, 21st, 31st, 101st
• 2nd, 22nd, 42nd, 102nd
• 3rd, 23rd, 53rd, 103rd
• 4th, 10th, 11th, 12th, 13th, 24th
• 111th, 112th, 113th, but 121st, 122nd, 123rd

Look at the final two digits first. If they are 11, 12, or 13, choose -th. Otherwise, the last digit determines the suffix.

Ordinals before nouns

Before a noun (a word for a person, place, thing, or idea), an ordinal works much like an adjective:

• the first day
• the second floor
• the twelfth question

Use the when the sequence is specific: the first bus of the morning. A possessive word or name replaces the: my first job, her second attempt, Alex’s third book. Do not say the my first job.

Ordinals can also stand alone when the noun is understood:

• I’ll take the second.
• Who arrived first?
• She came third.

In rankings after verbs such as come, finish, and place, English commonly omits the: Our team finished second. When identifying a specific item, the remains natural: The second was much cheaper than the first.

Dates

English dates may be written and spoken in different ways.

Style	Common written form	Common spoken form
Month first, common in the US	May 5 or May 5th	May fifth
Day first, common in Britain and elsewhere	5 May or 5th May	the fifth of May

In formal modern writing, style guides often prefer May 5 or 5 May without an ordinal suffix, although the date is still normally read with an ordinal: May fifth or the fifth of May. Forms with a suffix are also widespread, especially in informal writing.

Examples in Context

English example	Meaning	Note
Monday is my first day at the new job.	Monday begins my time in the job.	A possessive replaces the.
Our apartment is on the second floor.	The apartment is at floor number two.	A specific position takes the.
Please read the third paragraph.	Read paragraph number three.	Ordinal before a noun.
Take the first left after the bridge.	Turn left at the earliest available turn.	Common in directions.
Her birthday is May 5th.	Her birthday is on May fifth.	Month-first date.
The meeting is on the twelfth of June.	The meeting is on June 12.	Day-first spoken pattern.
She came third in the race.	Two competitors finished before her.	No the after came.
This is our twenty-first lesson.	This lesson has position 21.	Only the final element is ordinal.
He celebrated his fortieth birthday.	He became forty years old.	Forty → fortieth.
Room 101 is on the first floor.	The room number and floor position are different kinds of number.	101 is read as a label here, not an ordinal.
It was the hundredth anniversary of the school.	One hundred years had passed since the school began.	An exact hundred becomes hundredth.
For the second time, check the address carefully.	Check it again; this is attempt number two.	A repeated event.
I finished first, and Maya finished second.	I had the highest rank; Maya had the next rank.	Stand-alone ranking forms.
The eighth question is difficult.	Question number eight is difficult.	Spell it eighth, not eightth.

Common Mistakes

Using a cardinal number for a position

• Wrong: This is my three visit to London.
• Right: This is my third visit to London.
• Why: Three gives a quantity; third gives the visit’s position in a sequence.

Applying -th to every number

• Wrong: on the threeth floor
• Right: on the third floor
• Why: First, second, and third are irregular. They are not formed from one, two, and three with -th.

Misspelling irregular forms

• Wrong: the fiveth, eightth, nineth, or twelveth day
• Right: the fifth, eighth, ninth, or twelfth day
• Why: These common forms have spelling changes and should be learned as complete words.

Giving every part of a compound number an ordinal ending

• Wrong: the twentieth-first chapter
• Right: the twenty-first chapter
• Why: In compound numbers, only the last element becomes ordinal.

Choosing a suffix from the last digit alone

• Wrong: 11st, 12nd, 13rd
• Right: 11th, 12th, 13th
• Why: Numbers ending in 11, 12, and 13 always use -th. This includes 111th, 112th, and 113th.

Adding the after a possessive or in a ranking

• Wrong: It was the my first flight. / She finished the second.
• Right: It was my first flight. / She finished second.
• Why: A possessive already determines the noun, and rank expressions after finish normally have no article.

Usage Notes

Floors differ across English-speaking regions

In the United States and Canada, the street-level floor is usually the first floor. In Britain and many other countries, it is the ground floor, and the first floor is one level above it. This is a cultural numbering difference, not a different ordinal-number rule. When directions matter, confirm the building’s system.

Words or figures?

Both the twenty-first century and the 21st century are normal. Continuous prose often spells out short ordinals, while signs, lists, dates, rankings, and compact labels often use figures. Formal publications follow their own style guides. Avoid superscript as a requirement: plain 21st is clear and standard in digital text.

A numbered label is not always spoken as an ordinal. Room 12, Chapter 3, Platform 4, and Bus 10 often use cardinal numbers: room twelve, chapter three, platform four, bus ten. Compare the third chapter, which describes the chapter’s position.

First can describe time as well as rank

At first means “at the beginning”: At first, I was nervous. First can also organize instructions: First, open the app. Second, choose a lesson. In casual instructions, speakers often continue with then or next rather than listing every ordinal.

Beyond the Basics / Advanced Use

You do not need to master these patterns at A1, but they explain forms you will meet later.

Centuries and formal names

Century numbers are one higher than the first digits of most years: the years 1901–2000 belong to the twentieth century, and 2001–2100 belong to the twenty-first century. The phrase normally uses the.

Roman numerals after the names of monarchs and popes are spoken as ordinals: Elizabeth II is Elizabeth the Second, and Henry VIII is Henry the Eighth. The word the is spoken even though it is not written in the name.

Fractions

Many fraction names use an ordinal as the denominator (the bottom number, which shows how many equal parts make a whole):

• 1/3: one third
• 1/4: one fourth or one quarter
• 2/5: two fifths
• 7/10: seven tenths

Use a plural denominator when the numerator is greater than one: two thirds, not two third. The common exceptions are 1/2, one half, and the frequent alternative quarter for fourth.

A second and the second

Articles can change the meaning. The second question means the question in position two. A second question often means “another question”: May I ask a second question? Similarly, a third option can mean one more option in addition to two already mentioned.

Ordinals also appear in fixed or extended expressions: first aid, first language, second-hand, third party, and first-class. Their meanings may go beyond a simple physical sequence, so it is useful to learn each expression as a unit.

Practice Tips

1. Build two-way number pairs. Write ten cardinal numbers on cards and convert them aloud: five → fifth, twelve → twelfth, 32 → thirty-second. Then reverse the exercise.
2. Use real dates and sequences. Say birthdays, appointments, floors, and the order of tasks in your day. Practice both May fifth and the fifth of May.
3. Check compound endings. For a figure such as 113 or 121, look at the final two digits before adding the suffix. Say the complete form aloud to connect 121st with one hundred and twenty-first.

Related Concepts

• Prerequisite: Cardinal Numbers — learn counting forms such as one, two, three, and twenty-one before turning them into positions.