Translation guide
The English phrase 'red line' can refer to a literal red-colored line, a boundary or limit that should not be crossed, or a specific policy or principle that is non-negotiable. This guide helps learners express these concepts naturally in Japanese.
Referring to a physical line that is red in color, such as on a map, document, or surface.
The most direct translation for a literal red line. Use this for any physical red line.
地図に赤い線を引いてください。
Please draw a red line on the map.
A compound noun meaning 'red line'. Often used in contexts like editing, marking, or indicating boundaries on documents.
修正箇所に赤線を引いた。
I drew a red line at the corrections.
A point beyond which one should not go; a limit that, if crossed, will trigger serious consequences.
Literally 'a line that must not be crossed'. This is a natural way to express a red line in a figurative sense, emphasizing a strict boundary.
それは越えてはならない一線だ。
That is a red line that must not be crossed.
A loanword from English, used in political, diplomatic, or business contexts to mean a non-negotiable limit. Common in news and formal discussions.
政府はその問題をレッドラインと見なしている。
The government regards that issue as a red line.
Means 'boundary line' or 'limit line'. Can be used in technical or formal contexts, but less common for figurative red lines.
交渉の限界線を明確にした。
We clarified the red line in the negotiations.
A firm stance or rule that will not be compromised, often used in politics, business, or personal values.
Literally 'a line that cannot be conceded'. This is a very natural way to express a personal or organizational red line.
安全基準は譲れない一線です。
Safety standards are a red line for us.
Means 'a line that must be absolutely protected'. Emphasizes the non-negotiable nature of the boundary.
プライバシーは絶対に守るべき線だ。
Privacy is a red line that must be absolutely protected.
While '赤い線' is correct for a physical red line, using it for a figurative boundary can sound unnatural. Use phrases like '越えてはならない一線' or 'レッドライン' instead.
それは越えてはならない一線だ。
That is a red line.