Translation guide
The English idiom "walls have ears" warns that someone might be listening, even in a seemingly private place. In Japanese, this concept is expressed through a similar proverb, as well as various phrases and strategies to convey the idea of being overheard.
To caution someone that a private conversation might be overheard, often in a semi-public or untrusted environment.
A well-known Japanese proverb literally meaning "walls have ears, sliding doors have eyes." It is the closest cultural equivalent to "walls have ears" and is used to warn that secrets can easily be leaked.
The proverb 壁に耳あり障子に目あり is somewhat old-fashioned but still widely understood. In casual conversation, a phrase like 誰が聞いているかわからない is more natural.
Do not translate "walls have ears" literally as 壁は耳を持っている. It will not be understood as the idiom.
We shouldn't speak too loudly here. Walls have ears, you know.
A straightforward phrase meaning "you never know who might be listening." It is a more direct and modern way to express the same caution.
ここで秘密の話はやめよう。誰が聞いているかわからないから。
Let's not talk about secrets here. You never know who might be listening.
Means "we might be eavesdropped on." It directly states the risk of being overheard, suitable for cautious situations.
この部屋、防音じゃないから、盗み聞きされるかもしれないよ。
This room isn't soundproof, so someone might eavesdrop on us.
A strategy rather than a direct translation: "to lower one's voice." Often used as a precaution when the risk of being overheard is implied.
ちょっと声をひそめて。ここは壁が薄いから。
Lower your voice a bit. The walls are thin here.