Translation guide
This entry covers how to express 'a long period of time' in Japanese. It includes common nouns, adverbs, and phrases to describe extended durations, from neutral expressions to those emphasizing length or continuity.
To refer to a long period of time in a neutral or general sense.
A straightforward noun meaning 'long period' or 'extended period'. Suitable for both spoken and written contexts.
I returned from a long trip.
Often used as a prefix or in compounds to mean 'long-term'. Common in business and news.
We make a long-term plan.
A very common phrase meaning 'for a long time'. Used in everyday conversation.
Sorry to have kept you waiting for so long.
Similar to 長期間 but slightly more conversational. Emphasizes the length.
I worked abroad for a long period.
To stress that a period is unusually or extremely long.
Literally 'long years and months', used for periods spanning many years. Often carries a sense of endurance or passage of time.
This town developed over many long years.
Similar to 長い年月 but slightly more literary. Emphasizes the flow of time.
A long time has passed.
An adjective meaning 'long (time)' since something happened. Mostly used in the set phrase 久しぶり (long time no see) or in formal writing.
To describe an action or state that continues over a long period.
To express that something happens after a long interval.
The standard way to say 'after a long time' or 'for the first time in a while'.
I watched a movie for the first time in a long time.
長期間 (ちょうきかん) is more formal and often used in written or business contexts. 長い間 (ながいあいだ) is more conversational and commonly used in daily speech. Both mean 'a long period', but 長い間 is preferred when speaking casually.
While 長い時間の期間 is grammatically possible, it is unnatural. Use 長期間 or 長い間 instead.
久しく会っていない。
I haven't seen you for a long time.