The most common way to say "last year" in Japanese is 去年 (kyonen). This is the standard, everyday vocabulary word you will use when speaking with friends, family members, classmates, or coworkers in standard polite conversation.
However, Japanese is a language heavily influenced by context and formality levels. If you are reading a newspaper, writing an official business email, or delivering a formal speech, you will instead use the word 昨年 (sakunen). Both of these words mean the exact same thing and refer to the same timeframe, but sakunen projects a much more sophisticated, highly professional tone.

How to Use It in a Sentence
In Japanese grammar, relative time words—like last year, today, next month, or tomorrow—operate under a specific rule: they do not require a target time particle like に (ni). In English, we might say "in 2025," but for relative time, you simply state the word itself.
As a general rule, you should place kyonen or sakunen near the beginning of your sentence. This immediately establishes the timeframe for the listener before you introduce the action. If you want to emphasize that "last year" is the core topic you are discussing, you can attach the topic marker は (wa) directly to the word.
Here is how you can naturally structure sentences using both variations:
Using Kyonen (Everyday Speech)
去年、日本へ行きました。
(Kyonen, Nihon e ikimashita.)
Translation: I went to Japan last year.
去年、新しい仕事を始めました。
(Kyonen, atarashii shigoto o hajimemashita.)
Translation: I started a new job last year.
去年はとても忙しかったです。
(Kyonen wa totemo isogashikatta desu.)
Translation: Last year was very busy. (Note the use of wa to emphasize the timeframe).
Using Sakunen (Formal & Business)
昨年は大変お世話になりました。
(Sakunen wa taihen osewa ni narimashita.)
Translation: Thank you very much for your support last year. (This is a standard set phrase for New Year's business emails).
昨年のプロジェクトは成功しました。
(Sakunen no purojekuto wa seikou shimashita.)
Translation: Last year's project was successful.
While Japanese sentence structure is flexible—allowing you to place kyonen after the subject, such as Watashi wa kyonen...—keeping your time words at the beginning of the sentence is the most natural and foolproof method for language learners.



