it's common knowledge vs it's a common knowledge

The correct phrase is 'it's common knowledge.' The phrase 'common knowledge' is an uncountable noun and does not require an article before it.

Last updated: March 22, 2024 • 1881 views

it's common knowledge

This phrase is correct and commonly used in English.

This phrase is used to indicate that something is widely known or accepted by many people.

Examples:

It's common knowledge that the Earth revolves around the Sun.
It's common knowledge that smoking is bad for your health.
It's common knowledge that exercise is good for you.
It's common knowledge that water boils at 100 degrees Celsius.
It's common knowledge that Shakespeare wrote many famous plays.

Show examples from the web [+]

So it's common knowledge that she's his daughter?
Now, it's common knowledge that he's a friend of the cause, but nothing ties him.
So it's common knowledge on the street what Gibbons up to?
It's common knowledge the vic was shot in the face.
It's common knowledge about you and Elizabeth Tyson.
It's common knowledge you can get anything in the laundry.
It's common knowledge that a ninja mansion has traps.
It's common knowledge that my half-brother Cem is the favored child of my father the Sultan.
It's common knowledge that Madge and Brian intend to wed.
It's common knowledge among jew and gentile alike.
It's common knowledge, the fakirs of Bangladesh can meditate their circulatory systems to a virtual standstill.
But it's common knowledge that the last name of a masthead is most important.
I know it's common knowledge, but you have terrible taste in women... except for Devon!
It's common knowledge around town that Harrison Parker is fighting for its life.
It's common knowledge Arthur would lay down his life for any of his subjects.
It's common knowledge in my family that...
It's common knowledge in Thunder Bay you were living with Quill.
What...? It's common knowledge, the fakirs of Bangladesh can meditate their circulatory systems to a virtual standstill.

it's a common knowledge

This phrase is incorrect in English. 'Common knowledge' is an uncountable noun and does not require an article.

What Our Customers Are Saying

Our customers love us! We have an average rating of 4.79 stars based on 283,125 votes.
Also check out our 2,100+ reviews on TrustPilot (4.9).

"Thank you!"
Sachi Nakama July 2024
"I have literally been through chat, PI, claude, bard and bing and I got conflicting answers! Thank you! Human intelligence reigns!"
Retha July 2024
"Faster than AI"
CYNTHIA December 2023
"This was very helpful and I personally think this site is the best."
Kaden October 2023
"It was extremely thorough and very helpful!"
imperialelisa October 2023
"7 years without any disappointment. Always 100% satisfied. You guys are the best in the world at what you do. Thank you so much :)"
Zubair Alam October 2023
"In a world of text messages and online communication, this is great to have as a live tool. Thank you."
Selena October 2023
"Without textranch I would be stuck!"
宏祐 October 2023
"Accuracy and fast response. Personal comments from editor. Thank you."
Clh September 2023
"I wasn't aware of this service, it's fascinating and more reliable than standard IA tools available on the internet"
Arturo September 2023
"The fact that you can get reliable fast feedback on your texts."
Vinicius Antonio August 2023
"you guys are better than grammarly i'm being honest here"
ordinary July 2023
"OMG! This is really good than any other text correction tools I've used so far. Highly recommend this."
Vehan July 2023
"Very fast and accurate. thank you."
mojtaba July 2023
"I love this app because it's help to writing skills all of students ♥️"
Tarisini July 2023
"This was exactly the mistake I was looking for, the wording dind´t sound right at first. Better than grammarly!"
Ente July 2023
"The immediate help that I received was reassuring and very satisfactory. Thanks."
priiiyanshuu July 2023
"this helps A LOT for my studies."
kathnunez02 June 2023
"Woow!! I would never have expected such precision! Thank you soooo much!!"
Berta June 2023
"Real Time Editor and not AI. Many Thanks."
Priya June 2023
"The very first thing excites me about Textranch is how much your editors care."
sepideh June 2023
"The fact that texts are checked by human editors rather than by AI, etc. I appreciate this!"
Анна June 2023
"Feel welcome, immediate response, high quality feedback"
martin.roy June 2023
"This is the best app that I have ever seen"
Burulai May 2023

it's common knowledge vs it's a common knowledge