Quick Reference

Meaning & Definition

昨日 (kinou) pins down the day before today with a single, unambiguous word — no need for phrases like “the day before” or “last day.” Its two kanji tell a miniature story: 昨 marks something past, and 日 means sun or day, together painting a picture of “the day that has already passed.”

昨日 means “yesterday” — the calendar day immediately before today. It functions as a standalone time noun and typically appears at the start of a sentence or clause to set the time frame, much like English “yesterday” does.

In casual speech, 昨日 is almost always pronounced きのう (kinou). A second, more formal reading, さくじつ (sakujitsu), uses the same kanji and appears in written news, official documents, and formal announcements. Choosing さくじつ over きのう signals a deliberate shift toward formal register, the same way English might prefer “the previous day” in a report versus “yesterday” in conversation.

Because 昨日 is a time noun rather than an adverb, it does not require a particle in most sentences — it simply precedes the verb or topic: 昨日、雨が降った (It rained yesterday). Adding の turns it into a modifier: 昨日の会議 (yesterday’s meeting).

How to Use It

The two readings trip up many learners. In everyday speech always use きのう (kinou) — saying さくじつ (sakujitsu) in casual conversation sounds stiff and unnatural. Reserve さくじつ for written reports, news scripts, or formal presentations.

Word order is the other common pitfall. Unlike English, where “yesterday” can appear at the end of a sentence (“I saw her yesterday”), Japanese strongly prefers placing 昨日 at the very beginning: 昨日、彼女に会った. Putting it after the verb is grammatically possible but sounds awkward in natural speech.

Do not confuse 昨日 with 前日 (zenjitsu). 前日 means “the day before a specific reference point” (e.g., the day before an event), while 昨日 always means the day before today specifically.

Kanji Breakdown

昨日 is written with two kanji, each contributing directly to the meaning.

昨 (saku / きのう) is the character for “the previous” or “last.” Its left-side radical 日 (sun/day) combined with the right-side component 乍 (a phonetic element suggesting something cut short or passing quickly) together convey the idea of a day that has just gone by. 昨 appears in related time words such as 昨年 (sakunen, last year) and 昨夜 (sakuya, last night).

日 (nichi / jitsu / か / ひ) means “sun” or “day.” As the right component, it specifies that what passed is specifically a day — not a month or year. Together, 昨＋日 form a compound that precisely identifies the day immediately behind today.

Example Sentences

Cultural Context

Japanese structures time around a clean three-way contrast: 昨日 (kinou, yesterday) — 今日 (kyou, today) — 明日 (ashita, tomorrow). This trio is among the first vocabulary any learner encounters, and Japanese speakers rely on it constantly to anchor stories and reports in time without needing clock references. Weather forecasts on Japanese television, for example, routinely open with a comparison between 昨日の気温 (yesterday’s temperature) and today’s, treating 昨日 as a natural baseline for daily context.

In formal writing and broadcasting, the variant さくじつ (sakujitsu) replaces きのう. Newspaper headlines, NHK news scripts, and corporate press releases consistently use さくじつ to maintain a professional tone. This register split — one word in speech, another in formal text — is a recurring feature of Japanese that learners must navigate, and 昨日／さくじつ is one of the clearest examples of that pattern in everyday vocabulary.

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