Translation guide
In English, "a certain ..." is used to refer to someone or something specific but unnamed, often implying the listener doesn't know or it's not important to name. In Japanese, this concept is expressed through modifiers like ある, とある, or specific phrasing, depending on nuance and formality.
The speaker knows the identity but chooses not to name it, often because it's unknown to the listener or irrelevant.
The speaker hints that the unnamed person or thing has some special quality, often with a tone of mystery or significance.
Formal/literary. Implies 'a certain' with a nuance of distinction or importance. Often used in set phrases like さる人 (a certain person of note). Not used in everyday speech.
ある is the standard, neutral way to say 'a certain'. とある adds a literary or storytelling flavor, often found in novels or when setting a scene. In everyday conversation, ある is preferred.
One day, I ran into him at the station.
One day, I suddenly got a phone call.
A certain person told me that.
Slightly more literary or story-like than ある. Often used in narratives to introduce a specific but unnamed element. Can sound a bit dramatic or old-fashioned.
In a certain town, there lived a mysterious old man.
Used when you want to say 'a certain (named) ...' by actually giving the name or description. It's like 'a ... called ...'. Not a direct translation of 'a certain', but often used in similar contexts.
There was a call from a certain Mr. Tanaka.
In casual conversation, Japanese often omits 'a certain' entirely if the context makes it clear you're referring to something specific but unnamed. The vagueness is conveyed through intonation or phrasing.
The other day, I heard from a certain person...
It's a request from a certain noble person.
Means 'that certain' or 'the usual' when both speaker and listener know what is being referred to, often from previous context. It's like 'you-know-what'.
How did that certain matter go?
とある寒い冬の夜、一匹の猫が道を歩いていた。
On a certain cold winter night, a cat was walking down the street.
English speakers often want to insert 'a certain' for vagueness, but Japanese often conveys this through context or other structures. Using ある too frequently can sound unnatural. Consider whether you can simply use a noun without a modifier.
It's a story I heard from a certain friend...