A2
就 and 才 — sooner or later than expected
How 就 and 才 carry the speaker’s judgement about timing in Chinese rather than the timing itself, and why a 才 sentence usually takes no 了.
Neither of these words means anything on its own about when. The time word does that. 就 and 才 say what the speaker thinks of it: 就 that it was early, quick or easy, 才 that it was late, slow or hard.
他七点就来了。
Tā qī diǎn jiù láile.
He was here by seven.
他九点才来。
Tā jiǔ diǎn cái lái.
He didn’t come until nine.
Swap the times and the words swap with them. 七点才来 would mean seven was unreasonably late — which it might be, if the meeting was at six. Both words are adverbs and sit immediately before the verb.
The amount, not just the clock
The same pair covers effort and quantity, which is where the judgement is most visible.
我学了三年才学会。
Wǒ xuéle sān nián cái xuéhuì.
It took me three years to learn it.
他一个星期就学会了。
Tā yí ge xīngqī jiù xuéhuì le.
He picked it up in a week.
才 usually takes no 了
This is the rule worth memorising, because it is invisible from English. A sentence-final 了 announces a change — that things have moved on. 才 is a complaint about how long it took, which is a comment on the situation rather than news, and the two pull against each other.
他九点才来了。
他九点才来。
就 sentences take 了 happily — 他七点就来了 — because being early is exactly the sort of thing worth reporting as news. 才 wants to grumble, and grumbling does not need 了.
就 in a sequence
Its other everyday job: then, straight away. Two things, the second following hard on the first.
我一说他就懂了。
Wǒ yì shuō tā jiù dǒng le.
He got it the moment I said it.
下课以后我就回家。
Xiàkè yǐhòu wǒ jiù huí jiā.
I’ll go straight home after class.
The first of those is the 一…就 pattern, which is worth learning as a unit — as soon as A, then B.
才 for “only then”
Turned around, 才 marks a condition that had to be met first. English reaches for only … if or not until.
你吃完饭才能出去。
Nǐ chīwán fàn cái néng chūqu.
You can go out only when you’ve finished eating.
就 in the same slot would make it sound easy and immediate; 才 makes it a condition. Which is the whole difference between these two words in one sentence.