There are two kinds of numbers in English – cardinal numbers and ordinal numbers.

We use these numbers in different ways.

We use cardinal numbers for the quantity of something.

Here are some examples of cardinal numbers.

• one (1)
• two (2)
• three (3)
• ten (10)
• fifty-five (55)
• ninety-two (82)
• five hundred and sixty-six (566)

Example Sentences

• I have one dollar.
• She has three brothers.
• They have 50 days to decide.
• A week has seven days.

Note: We usually write the number 1-10 (one, two, three, etc.), and for all numbers bigger than ten we use the digits (55, 56….958, etc.)

We use ordinal numbers to talk about order or position of something.

Here are some examples of ordinal numbers.

• first (1st)
• second (2nd)
• third (3rd)
• fourth (4th)
• fifth (5th)
• sixth (6th)
• seventh (7th)
• eighth (8th)
• ninth (9th)
• tenth (10th)
• eleventh (11th)
• twelfth (12th)
• thirteenth (13th)
• fourteenth (14th)
• fifteenth (15th)
• sixteenth (16th)
• seventeenth (17th)
• eighteenth (18th)
• nineteenth (19th)
• ninety-first (91st)
• fifty-second (52nd)
• twenty-third (23rd)
• eighty-fourth (84th)
• forty-fifth (45th)
• sixty-sixth (66th)
• seventy-seventh (77th)
• thirty-eighth (38th)
• ninety-ninth (99th)
• one-hundred and first (101st)
• six-hundred and twelfth (612th)

Here are the most common times that we use ordinal numbers.

1. Dates

• It is August 23rd. (twenty-third)
• My birthday is on January 29th. (twenty-ninth)
• The concert in on May 1st. (first)

2. Order

• I finished in first place in the competition.
• You will go second.
• He will present his idea third and you will present your idea fourth.
• I am first in line and he is fifth in line.

3. Birthdays and Anniversaries

• This is their twentieth wedding anniversary.
• This is the boy's seventh birthday.

4. Counting the number of times

• This is the third time that I have seen this movie.
• This is my first time visiting Europe.
• This is the second time that she has called today.

These kinds of English grammar points are important details if you want to be a fluent English speaker. Do not worry too much about them but pay attention to them and try to use them correctly. Knowing the difference between cardinal numbers and ordinal numbers will help your English sound more natural.