又⋯⋯了
yòu …… le
Expressing "again" in the past with "you"
又 is "again" for repetitions that have already happened.
又 + Verb + 了
How it works
你又迟到了 — you're late again. The 又 and the closing 了 work as a pair.
The split with 再 is the thing to remember: 又 looks back at a repetition that occurred, 再 forward to one that hasn't.
又 often carries mild exasperation, which 再 does not.
Examples
nǐ yòu chí dào le
你又迟到了。
You're late again.
tā yòu wàng le dài yào shi
他又忘了带钥匙。
He forgot his keys again.
jīn tiān yòu xià yǔ le
今天又下雨了。
It's raining again today.