才
Reach for this when something happened LATER, SLOWER, or under more restrictive conditions than you'd expect. 才 ('only then, not until') marks an action as late or hard-won. 'He didn't come home until 9pm,' 'Only then did I understand,' 'You have to study before you'll get it' — all 才 territory. The flip side of 就 ('right away, easily'). Neutral register, used constantly in everyday Chinese.
Structure
[CONDITION / TIME], Subject + 才 + Verb
cái
How to Think About It
才 is the 'late/hard' marker; 就 is the 'soon/easy' marker. Same sentence, swap one for the other and the speaker's whole attitude flips. 他八点就回家了 = 'He got home as early as 8pm.' 他八点才回家 = 'He didn't get home until 8pm.' No 了 typically follows 才 — the late-ness already implies the action just happened or is being noted.
Examples
他晚上十点才回家。
Tā wǎnshàng shí diǎn cái huíjiā.
He didn't get home until ten at night.
学了五年中文，我才能看懂这本书。
Xué le wǔ nián Zhōngwén, wǒ cái néng kàn dǒng zhè běn shū.
Only after five years of studying Chinese am I able to understand this book.
知道了原因，你才不会再生气。
Zhīdào le yuányīn, nǐ cái bù huì zài shēngqì.
Only once you know the reason will you stop being angry.
Common Mistake
Learners add 了 after the 才 verb because the action is in the past. With 才, the 了 usually disappears — the 'only just' meaning already does the job, and adding 了 makes it sound off.
他晚上九点才回家了。
他晚上九点才回家。
Don't Confuse With
就
Opposite vibe — 'as early as / right away / easily.' Same slot, opposite meaning. Pick 才 for late/hard, 就 for early/easy.
只
Means 'only' in quantity ('only three apples'). 才 is 'only' in time or condition ('only after...').
刚刚
'Just now' — neutral on whether it was late. 才 always carries the 'finally / not until' editorial tone.
Practice
Fill in: 他晚上十一点____回家。
Show answer
才
Fill in: 我学了三年，____能说一点中文。
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才
Arrange: 才 / 我 / 看完 / 这本书 / 现在
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我现在才看完这本书。
Translate to Chinese: I didn't understand until he explained it.
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他解释了，我才明白。
Write a sentence with 才 about something that took longer than expected.
Show answer
我等了一个小时，他才来。
Hear It in Real Episodes
This pattern appears in 2 Fluentide episodes: