21st vs 21th

The correct phrase is "21st." The suffix "st" is used for ordinal numbers ending in 1 (e.g., 1st, 21st, 31st). The suffix "th" is used for most other ordinal numbers.

Last updated: April 09, 2024 • 2077 views

21st

This phrase is correct. The suffix "st" is used for ordinal numbers ending in 1.

Use "21st" when referring to the ordinal number 21 in a date or sequence.

Examples:

The 21st of December is the winter solstice.
She finished in 21st place in the race.

Show examples from the web [+]

The new Memorial Hospital includes 21st Century technology.
Fast forward to 21st century China.
The Harmony Technology is built using 21st century Quantum Physics.
Earth, 21st century by the looks of it.
Welcome to a 21st century custody battle.
Especially with his 21st birthday coming up.
It was dated Portia's 21st birthday.
And the last one was her 21st.
We made 21st century money, and that was groundbreaking.
You'll work for us until your 21st birthday.
Yes, it was my 21st birthday.
But yesterday was my 21st birthday.
On my 21st birthday, just you and me...
I spent my 21st birthday in jail for that one.
North Korea occupies the entire 21st floor, which is locked down tight.
This bloke's made a 21st century version of his portrait.
Claire gave Adam this watch for his 21st birthday.
The morning after Jane's 21st birthday was somewhat less festive than the night before.
If I remember correctly, your old man also worked the 21st.
My grandmother gave me this on my 21st birthday.

Alternatives:

21st
twenty-first
the 21st

21th

This phrase is incorrect. The suffix "th" is not used for ordinal numbers ending in 1.

Show examples from the web [+]

Our slogan for the 21th century:
Opening of 21th PriMed with the audience award
2010 The 21th International Youth Prayer Festival, Medjugorje, 1. - 6.
21th edition of the festival of sacral art
It is therefore viewed as one of the most serious health problems in the 21th century, consuming over 6% of European health care budget.
Through natural processes described here should be probably explained one of the greatest imaginable mystery of 20th - 21th century - Crop Circles.
Dehon, in the 21th century Print this page 19/06/2014 Spiritual path for lay dehonians.
Fabric Light Box forever 21th century led sanp open aluminum alloy
The 21th edition of the Winter Cup which took place, as usual, on the Italian circuit of Lonato, was a formidable success.
The 64 km tunnel is a 21th century pioneering piece of engineering and it will improve the viability of public and freight transport in the heart of Europe.
The 21th edition of GeoFluid, which has been held in October, showed, this year too, a considerable increase in number of visitors, customers and dealers from abroad looking for our Made in Italy innovation.
Company Toyota - for the year fell from seventh to 21th place, worsening performance
Two solo exhibitions by Zach Blas and Heather Dewey-Hagborg in Eindhoven Biotechnology, AI and the Internet of Things are shaping the 21th century as we speak.
Submissions are closed for the 21th edition of PriMed festival
In several countries, on March 21th events will took place.
Permanent color is the hype of the 21th century.
In collaboration with VCC Enrico Bernardi.Wednesday, September 21th at 21.
February 21th is the day dedicated to mother language.
Even if he means the 21th century.
As of June 21th, that check has not yet been processed.

Alternatives:

21st
twenty-first
the 21st

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