一昨日
おととい · ototoi · JLPT N5 · noun
yesterday
📅 一昨日 = one + yesterday (昨日): one day further back than yesterday
昨日 is yesterday; putting 一 (one) in front steps back one more day. The native reading ototoi comes from older ototsui: oto (distant, far side) + tsu (old possessive) + hi (day), so literally the far-off day.
一 — single horizontal stroke
一 is one of the simplest pictographs in Chinese, depicting a single horizontal line to represent the number one. It has retained essentially the same form since oracle bone script over 3,000 years ago. By extension it also means 'first,' 'whole,' or 'same.'
日 — pictograph of the sun
日 is a pictograph of the sun, originally drawn as a circle with a dot or stroke inside representing the sun's substance. Over time the round shape was squared off into the modern rectangular form. It means 'sun' and by extension 'day'.
いっさくじつ · issakujitsu · JLPT N2 · noun
yesterday
📅 一昨日 = one (一) + yesterday (昨) + day (日): one day past yesterday
昨日 (sakujitsu) is the formal word for yesterday. Put 一 in front and you go one more day back. In speech you will usually hear おととい (ototoi) for the same kanji. いっさくじつ is the formal reading, used in news and business.
一 — single horizontal stroke
一 is one of the simplest pictographs in Chinese, depicting a single horizontal line to represent the number one. It has retained essentially the same form since oracle bone script over 3,000 years ago. By extension it also means 'first,' 'whole,' or 'same.'
日 — pictograph of the sun
日 is a pictograph of the sun, originally drawn as a circle with a dot or stroke inside representing the sun's substance. Over time the round shape was squared off into the modern rectangular form. It means 'sun' and by extension 'day'.