Yesterday
noun
The yesterday day is yesterday. What a blast from the past!
きのう, さくじつ
Oof. The reading for this word makes no sense. You'll have to forget everything you've learned about the readings of the kanji and just go straight up mnemonic for the word on its own. Okay. Think about what you did yesterday, all day. You played keno (きのう), gambling away your grandmother's money. Yesterday was the worst day ever because you lost everything playing Keno. Today is different, not like yesterday, right?
昨日はジムに行きました。
I went to the gym yesterday.
昨日は、夜中から朝まで、ずっとカラオケしてました。
Yesterday, I sang karaoke all night until morning
昨日の日本代表の試合、すごかったね！見た？
Yesterday's game of the Japanese national team was amazing, right? Did you watch it?