Not until

Not untill

...

倒裝

1. 他直到做完工作才回家。
Not until he finished the job did he go home.

2. 直到上週日她才還我錢。
Not until last Sunday did she return me money.

例句：直到要付咖啡錢時，我才發現我的錢包早就不見了。

I didn't realize that my wallet was long gone until I was ready to pay for my coffee.
=
Not until I was ready to pay for my coffee did I realize that my wallet was long gone.

Not until 提至句首後，需搭配倒裝句：助動詞 ( did ) + 主詞 ( I ) + 動詞原形 ( realize )。