Translation guide
How to express that something is widely known or obvious in Japanese, from neutral facts to idiomatic phrases.
To say that something is generally known by most people.
A neutral, common phrase meaning 'a widely known fact'. Suitable for both spoken and written contexts.
それは周知の事実です。
That is common knowledge.
To emphasize that something is so obvious it doesn't need to be stated.
To use a set phrase or proverb to express that something is universally known.
A proverb meaning 'everyone knows except the husband', used when something is widely known but the person most concerned is unaware. Equivalent to 'it's an open secret'.
彼の浮気は知らぬは亭主ばかりなりだ。
His affair is an open secret.
常識 implies something that should be known as part of basic social knowledge, while 周知の事実 simply states that a fact is widely known without the normative nuance.
遅刻しないのは常識だ。
It's common sense not to be late.
彼が辞めたのは周知の事実だ。
It's common knowledge that he quit.
The direct translation '共通の知識' is not natural Japanese and should be avoided. Use the phrases above instead.
Means 'common sense' or 'common knowledge'. Often used for things that everyone is expected to know.
そんなことは常識だ。
That's common knowledge.
Literally 'everyone knows'. A straightforward, conversational way to say something is common knowledge.
その話は誰でも知っているよ。
Everyone knows that story.
Means 'it goes without saying' or 'needless to say'. Very common in both speech and writing.
言うまでもなく、健康は大切だ。
Needless to say, health is important.
Means 'obvious', 'natural', or 'a matter of course'. Very common in casual conversation.
それは当たり前のことだ。
That's a matter of course.
An idiomatic expression meaning 'as clear as day' or 'obvious'. Literally 'clearer than seeing fire'. Used for emphasis.
彼が嘘をついているのは火を見るより明らかだ。
It's obvious that he is lying.