昨日ある質問をここでしました。
その中で使った動詞quittedは誤りで、正しくはquitだと複数の方から指摘されました。
そこで、5つの辞書で調べました。
quit-quit-quitしか書いていないのは1つだけでした。ここで検索してもquitを使う人が多いようです。
これについて説明をお願いします。

Sehen Sie eine Übersetzung

Good question! Thank you for asking

I believe that [quitted] is, as you stated, listed in some dictionaries as a legitimate word.

However, it could be due to regional preferences that some native English speaking countries may differ in the use of one word over the other [UK / US / Aus / etc.]. It also could be that it was used more in the past, but its use may have diminished over time in favor of a different word.

For example, in the United States many people will prefer to use the word [quit] as a multi-tense word and rarely is [quitted] used.

*That is right! From my understanding, BrE = British English*

例
"They will most likely [quit] soon, I heard about it yesterday." - potential future

"I am [quitting]!" - present participle

"I [quit] smoking over 3 months ago and I feel amazing!" - past

I hope this helps!