Transitive verb and Ichidan verb
わすれる
ごめんね、カナエちゃん。みんなカナエちゃんがどれだけ努力したのかすっかり忘れちゃってたんだ。
Sorry, Kanae. We all totally forgot about how much effort you put into it.
危うくコウイチの顔を忘れる所だったよ。
I almost forgot Koichi's face.
もう忘れなって。過ぎてしまったことは今さらどうにもならないんだから。
Forget about it. It’s water under the bridge.
This word consists of kanji with hiragana attached. Because the hiragana ends with an う sound, you know this word is a verb. The kanji itself means forget so the verb vocab version is to forget.
Since this word consists of a kanji with hiragana attached, you can bet that it will use the kun'yomi reading. You didn't learn that reading with this kanji, so here's a mnemonic to help you: Wait, what was (わす) the reading? I forget... What was it?