才 vs 就 and 已经 vs 曾经 encode whether something happened earlier or later than expected, and whether it still matters now. Both pairs are top-10 HSK 4 confusables. Part of the 15 high-frequency HSK 4 traps collection.
高频
14. 才 vs 就 — later vs earlier than expected
Both 才 and 就 mark the speaker's evaluation of timing, but in opposite directions. 才 = "only then / not until" (later than expected). 就 = "already / as early as" (earlier than expected). Same time, opposite spin.
就 = earlier than expected: 他八点就来了。 Tā bā diǎn jiù lái le. — "He came as early as 8 — earlier than I expected."
才 = later than expected: 他八点才来。 Tā bā diǎn cái lái. — "He didn't come until 8 — later than I expected."
就 with quantity: 这件事一句话就说清楚了。 — Said in just one sentence (efficiently).
才 with quantity: 我说了三遍，他才听懂。 — Took three repetitions before he understood (slowly).
了 rule: 就 sentences usually take 了 (就…了); 才 sentences usually do NOT take 了 because 才 already conveys "completed action that happened late." HSK 4 排序 (Q56-65) and 选词填空 (Q46-55) test this exact split.
15. 已经 vs 曾经 — current relevance vs past experience
Both translate as "already / once" in English, but Chinese splits them by whether the past action's result is still relevant. 已经 + 了 = the result holds NOW. 曾经 = a past experience that is no longer current.
已经 = result holds now (still true): ✓ 他已经毕业了。 Tā yǐjīng bìyè le. — "He has graduated (and is now a graduate)." Current state.
✓ 我已经吃完饭了，你呢？ Wǒ yǐjīng chī wán fàn le, nǐ ne? — "I've already finished eating, how about you?" Recent completion, result still holds.
✓ 这本书我已经看过两遍了。 Zhè běn shū wǒ yǐjīng kàn guò liǎng biàn le. — "I've already read this book twice." Past action, the experience is current/relevant.
曾经 = past experience, no longer current: ✓ 他曾经是老师，现在是医生。 Tā céngjīng shì lǎoshī, xiànzài shì yīshēng. — "He used to be a teacher, now he's a doctor." Past state, no longer true.
✓ 我曾经去过北京，那是十年前的事了。 Wǒ céngjīng qù guò Běijīng, nà shì shí nián qián de shì le. — "I once went to Beijing — that was 10 years ago." Distant past experience.
✓ 这家餐厅曾经很有名，但现在已经关门了。 Zhè jiā cāntīng céngjīng hěn yǒumíng, dàn xiànzài yǐjīng guānmén le. — "This restaurant was once famous, but it has closed now." Past state, no longer true.
Quick test: Ask "is the result still true now?" If YES → 已经…了. If NO (changed since) → 曾经. 已经 nearly always pairs with 了. 曾经 rarely takes 了 — it specifically marks a finished, no-longer-relevant past. HSK 4 选词填空 hides this in autobiographical or historical passages.
"他八点___来。" — If 8 o'clock is later than the speaker expected:
才 = "not until / only then" (later than expected). 就 = "as early as" (earlier than expected). Same time, opposite spin. Note: 才 sentences usually do NOT take 了; 就 sentences usually DO take 了.
现在是医生 signals the past state is no longer true → 曾经 (past experience, no longer current). 已经 would imply the result still holds, which contradicts 现在是医生.
