Translation guide
How to express pretending not to know something in Japanese, from casual to formal situations.
The speaker deliberately acts as if they are unaware of something.
The most common and neutral way to say 'pretend not to know'. Literally 'do a pretense of not knowing'.
He pretended not to know about it.
Please don't pretend not to know.
Casual, often used when someone ignores something obvious. '知らん' is a colloquial contraction of '知らない'.
She pretended not to know me even when she saw me.
To play dumb, feign ignorance. Often used when someone is being evasive or pretending not to understand.
Don't play dumb, you know, right?
To insist that one doesn't know, often in a defensive or stubborn way.
He insisted to the end that he didn't know.
Specifically ignoring or acting as if you don't recognize a person.
Literally 'make a face of not knowing', used when you see someone but pretend you don't know them.
I ran into my ex on the street, but I pretended not to know him.
Similar to 知らない顔をする, but with a nuance of feigning innocence or nonchalance.
He passed by with an innocent look, pretending not to know.
Feigning ignorance about a specific subject or information.
Emphasizes knowing nothing at all about the matter.
He pretended to know nothing about the plan.
Pretending not to have heard about something, often used when someone brings up a topic you want to avoid.
I pretended not to have heard that rumor.
知らないふり is standard and can be used in any situation. 知らんぷり is more colloquial and often implies a deliberate, sometimes rude, ignoring of something obvious.
The child pretended not to know when he was about to be scolded.
Do not directly translate 'pretend not to know' as 知らないことを装う (しらないことをよそおう). While grammatically possible, it is unnatural. Use 知らないふりをする instead.