再 or 又: again, ahead or behind
Both mean “again”. 再 is for a repetition that has not happened yet; 又 is for one that already has, and it almost always brings 了 with it.
结构
再 + 动词（重复尚未发生） ｜ 又 + 动词 + 了（重复已经发生）
讲解
本文中的中文词语都可以激活，查看词典释义。
English has one word for both, which is why this pair needs deliberate practice. The dividing line is time: looks forward, looks back.
is for a repetition that is still to come: “Let’s talk about it again tomorrow”, “I’ll come again next month”, “Say that again, please.” Because the event has not happened, a sentence never carries .
is for a repetition that has already taken place: “He was late again yesterday”, ！ “You’ve forgotten again!” The final is part of the package; without sounds unfinished.
The practical consequence is that requests and suggestions always take , never . is impossible: you are asking for something that has not happened yet. Conversely, a report of the past takes : is wrong for “I’ll come again tomorrow”.
has two further uses worth knowing. It marks the next step in a sequence — ， — and it means “more, in addition”: “another cup, please”, . With modal verbs it follows them: .
has a second life as the paired ……, where it links two qualities rather than repeating an event. That use has nothing to do with “again” and is worth keeping separate in your mind.
正确
Say each one out loud before moving on. The audio is a reference pronunciation, not a model to imitate exactly — match the tone contour, not the voice.
明天再说吧。明天再說吧。
Míngtiān (second tone, rising) zài (fourth tone, falling) shuō (first tone, high and level) ba. (neutral tone)···
Let’s talk about it again tomorrow.
他昨天又迟到了。他昨天又遲到了。
Tā (first tone, high and level) zuótiān (second tone, rising) yòu (fourth tone, falling) chídào (second tone, rising) le. (neutral tone)···
He was late again yesterday.
请再说一遍，好吗？請再說一遍，好嗎？
Qǐng (third tone, dipping) zài (fourth tone, falling) shuō (first tone, high and level) yí (second tone, rising) biàn, (fourth tone, falling) hǎo (third tone, dipping) ma? (neutral tone)···
Could you say that once more, please?
错误 — 常见错误
These sentences are wrong. They are printed here on purpose, each one paired with the repair and the reason, because the error you can recognise is the error you stop making.
不太对
Incorrect sentence: 他昨天再迟到了。
正确
Correct sentence: 他昨天又迟到了。
为什么: The lateness already happened, so the word is 又 — and it keeps its 了. 再 can only point at a repetition still to come.
不太对
Incorrect sentence: 请又说一遍。
正确
Correct sentence: 请再说一遍。
为什么: A request concerns something that has not happened yet, so it always takes 再. 又 cannot appear in an instruction or a plea.
不太对
Incorrect sentence: 我明天又来。
正确
Correct sentence: 我明天再来。
为什么: Tomorrow has not happened, so the forward-looking word 再 is required. 又 would place the visit in the past.
对比
Most errors with this pattern are not errors about this pattern — they are a neighbouring pattern arriving at the wrong moment. Read these side by side.
The 又 of 又…又… is not the “again” 又. In 这个房间又大又亮 nothing is repeated: the two 又 simply link two qualities of one room. The giveaway is that repetition-又 appears once and normally drags a 了 along with it (他又迟到了), whereas paired-又 appears twice and never takes 了. If you see a single 又 with 了 at the end, it means “again”; if you see two 又 with bare adjectives between them, it means “both”.
Both this and that: 又…又… →小测验
第 1 题 / 3总分: 0
Choose the word that fits: the speaker is asking for a repetition now.
对不起，请 ___ 说一遍。