昨日（きのう、kinou）
- yesterday

The Japanese word 昨日 (きのう, きのう) means "yesterday." It refers to the day immediately preceding the current day. It's used to specify a time in the past.

⚫︎昨日、映画を見ました。 Translation: I watched a movie yesterday. ⚫︎昨日は雨でした。 Translation: It was raining yesterday. ⚫︎昨日の宿題は難しかった。 Translation: Yesterday's homework was difficult.

昨日 (きのう, きのう) is used in conversations and writing to describe events or conditions that occurred on the previous day. It typically comes before the time or action it refers to. For example, you would say 昨日、学校に行きました (I went to school yesterday). It can be used in both formal and informal situations.

⚫︎The word 昨日 is primarily written using kanji: 昨日. ⚫︎The reading is きのう in hiragana. ⚫︎There is no katakana version for 昨日. ⚫︎There are no variations in okurigana (suffix hiragana).

⚫︎There are no direct synonyms for "yesterday" in Japanese. However, you could use phrases like 前の日 (まえのひ, the previous day) to refer to the same concept.

⚫︎The antonym of 昨日 (きのう, きのう) is 今日 (きょう, today) and 明日 (あした or あす, tomorrow).

昨日はとても暑かったです。 ・Translation: It was very hot yesterday. ・Explanation: This sentence uses 昨日 to describe the weather conditions on the previous day.

昨日はたくさん勉強しました。 ・Translation: I studied a lot yesterday. ・Explanation: This sentence expresses the amount of studying done the previous day.

The word 昨日 (きのう, きのう) is composed of two kanji: 昨 (saku), meaning "previous" or "last," and 日 (hi or nichi), meaning "day" or "sun." Therefore, 昨日 literally means "the previous day."