Translation guide
The English word "alert" can be a noun, adjective, or verb. This guide covers the main meanings: a warning or alarm, being watchful and attentive, and the act of warning someone. Japanese uses different words and phrases depending on the part of speech and context.
A signal or notification that warns of danger or an urgent situation.
General term for an official warning or alarm, such as a weather alert or emergency alert.
気象庁が大雨警報を発令した。
The meteorological agency issued a heavy rain alert.
Loanword from English, often used in IT or business contexts for notifications or alerts on devices.
スマホに地震のアラートが届いた。
An earthquake alert came through on my smartphone.
A lower-level advisory or watch, less urgent than 警報. Used in weather contexts.
乾燥注意報が出ている。
A dry weather advisory is in effect.
Can mean alert as a state of vigilance, but also used in compounds like 警戒警報 (warning alert). More often used as a noun meaning 'vigilance'.
警戒レベルが引き上げられた。
The alert level was raised.
Describing a state of being fully aware and ready to act, often mentally sharp.
Literally 'being vigilant', used for being on guard against danger or threats.
警察はテロに警戒している。
The police are alert to terrorism.
Adverb meaning 'without letting one's guard down', often used in the phrase 油断なく見張る (keep a sharp lookout).
彼は油断なく周囲を見張っていた。
He kept an alert watch on his surroundings.
Means 'mentally alert' or 'sharp', focusing on clear thinking rather than vigilance.
朝はコーヒーを飲むと頭が冴える。
In the morning, coffee makes me alert.
To inform someone of a danger or problem, often officially.
To warn or caution someone about something. The most direct verb for 'alert' as an action.
医者は患者に副作用の可能性を警告した。
The doctor alerted the patient to possible side effects.
To call attention to something, to urge caution. Softer than 警告する.
政府は国民に詐欺に注意を促した。
The government alerted the public to the scam.
To report or notify, often to authorities. Can be used in the sense of alerting the police.
不審者を見かけたら警察に通報してください。
If you see a suspicious person, alert the police.
警報 (warning) is for severe conditions that may cause damage. 注意報 (advisory) is for less severe conditions that still require caution. For example, a 大雨警報 means heavy rain that could lead to disasters, while 大雨注意報 means heavy rain that needs attention but is less dangerous.
アラート is mainly for electronic notifications or IT contexts. Using it for a weather warning or a person's vigilance sounds unnatural. Stick to 警報 or 警戒 for those.
Adjective meaning 'cautious' or 'wary', implying a habitual alertness.
彼女は用心深い性格だ。
She has an alert and cautious nature.