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 • 1861 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.

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