He not only made one of two mistakes, he made three.
❶It’s not just one or two. (一つや二つじゃない)。
❷He not only made 1 or 2 mistakes, he made 3.
(彼は一つや二つの失敗ではなく、三つもだよ!)
It wasn’t just one or two typos, it was three and in one email.
(誤字は一つや二つではなく、一つのメールに3つだよ)。
誤字−typo
My coworker always makes small mistakes.
Yesterday, he not only made one or two typos. he made three and in one email.
「私の同僚はいつも小さいミスをする。昨日、誤字は一つや二つではなく、一つのメールに3つもだよ)。