One, two, three … are cardinal numbers.
First, second, third … are ordinal numbers.
Ordinal numbers normally show the order or sequence of something or someone.
You can normally create ordinal numbers by adding -TH to the end of a cardinal number.
Four – Fourth
Sixteen – Sixteenth
The main exceptions are with the numbers 1, 2, and 3.
one – first
two – second
three – third
Also you need to be careful with the spelling of some ordinal numbers:
five – fifth (not “fiveth“)
nine – ninth (not “nineth“)
When do we use ordinal numbers?
Ordinal numbers are normally used for:
Dates
We use ordinal numbers when giving a date.
Her birthday is on the 29th. (Twenty-ninth)
Their Independence Day is on the 4th of July. (Fourth of July)
Sequence or Order
We use ordinal numbers when we want to show the order or position of someone or something in a sequence.
San Francisco finished second in the league last year.
I came third in the race.
This is the first time it has happened.
Floors of a building
Our office is on the ninth floor.
She lives on the second floor.
Birthday Celebrations
A person’s 15th birthday is an important celebration in Mexico.
He had a huge party for his twenty-first birthday.
Centuries
Shakespeare was born in the 16th century.
The Renaissance was a period in European history from the 14th to the 17th century.
Kings and Queens
For the name of a king or queen in written English, Roman numerals are used. However those Roman numerals are said as an ordinal number in spoken English.
Henry VIII (Henry the Eighth)
Louis XVI (Louis the Sixteenth) was the last king of France before the fall of the monarchy during the French Revolution.
List of Ordinal Numbers
We have included all of the ordinal numbers from 1st to 31st because they are needed when you give a date in English.
The ordinal numbers from 1st to 31st in English are:
