HSK 2
又 (yòu) vs 再 (zài): Again in Chinese
又 and 再 both mean "again", split by time. 又 is for a repeat that already happened (他昨天又迟到了 — he was late again). 再 is for an intended repeat still to come (明天再来 — come again tomorrow). 又 can also appear with a future time when the speaker predicts another recurrence, as in 明天又要下雨.
STRUCTURE
又 repeated past, 再 repeat in future
When to use 又/再 — and when not
Use it when
- 又 for a repeat that already happened: 他又忘了。
- 再 for a repeat still to come: 请再说一遍。
- 再 after 不 / 别 for "not again": 别再迟到了。
Don't use it when
- 再 for a repeat that already happened — use 又: 他昨天又来了, not 昨天再来了。
- Using 又 for an instruction or request to repeat an action — requests normally use 再: 请再说一遍。Future predictions can still use 又: 明天又要下雨。
- Putting them after the verb — both are adverbs and sit before it: 又迟到, 再说。
Right vs. wrong
他昨天再迟到了。
他昨天又迟到了。
再 used for a repeat that already happened
再 is for a future repeat; a repeat that already happened takes 又. The 昨天 and 了 mark it as done, so 又 is required.
请说再一遍。
请再说一遍。
再 placed after the repeated verb
再 is an adverb and normally comes before the verb it modifies. In a request to repeat the action, say 请再说一遍。
Examples
他又迟到了。
Tā yòu chídào le.
He was late again.
请再说一遍。
Qǐng zài shuō yí biàn.
Please say it again.
我昨天又见到他了。
Wǒ zuótiān yòu jiàndào tā le.
I saw him again yesterday.
明天再聊。
Míngtiān zài liáo.
Let's talk again tomorrow.
别再迟到了。
Bié zài chídào le.
Don't be late again.
Common mistakes
他昨天再迟到了。
Tā zuótiān zài chídào le.
A past repeat takes 又: 他昨天又迟到了。
请说再一遍。
Qǐng shuō zài yí biàn.
再 goes before the repeated verb: 请再说一遍。
请又说一遍。
Qǐng yòu shuō yí biàn.
About to repeat → 再: 请再说一遍。
Think you've got it?
Write your own 又/再 sentence and check that grammar point first.
又 (yòu) vs 再 (zài): Again FAQ
What is the difference between 又 and 再?
As a beginner default, 又 describes a recurrence viewed as having happened (他又来了), while 再 introduces an intended repeat still to come (你再来). A predicted future recurrence can still use 又, as in 明天又要下雨.
Can 又 be used with a future time?
Yes, when predicting that something will recur: 明天又要下雨 (it is going to rain again tomorrow). For a request or intended repeat, use 再: 明天再来。
How do I say "don't do it again"?
别再 + verb: 别再迟到了 (don't be late again), 别再说了 (don't say it again). 再 fits because you're talking about a future repeat.