Some of the most useful expressions in spoken Mandarin are potentials that have frozen solid. They still wear the V得/不C shape of the potential complement, but they no longer behave like productive grammar — they carry idiomatic meanings you cannot fully reassemble from the parts, and several of them survive only in the negative. The efficient move is to memorize each as a whole word: 来不及 "there's no time," 受不了 "can't stand it," 了不起 "amazing," 怪不得 "no wonder," 恨不得 "wish one could," 巴不得 "can't wait for." This page collects the high-frequency ones and flags the traps.
Frozen, not free — learn them whole
Here is the core set. Notice the last column: some have a living affirmative partner, but the most idiomatic ones live only as negatives.
| Idiom | Literal parts | Idiomatic meaning | Affirmative partner? |
|---|---|---|---|
| 来不及 (lái bu jí) | come + not + reach | not enough time / too late | yes — 来得及 (in time) |
| 受不了 (shòu bu liǎo) | bear + not + finish | can't stand it | yes — 受得了 (can bear) |
| 了不起 (liǎo bu qǐ) | settle + not + rise | amazing, remarkable | no (positive meaning!) |
| 怪不得 (guài bu de) | blame + not + able | no wonder | no |
| 恨不得 (hèn bu de) | hate + not + able | wish desperately one could | no |
| 巴不得 (bā bu de) | cling + not + able | can't wait for / only too glad | no |
| 大不了 (dà bu liǎo) | big + not + finish | at worst / no big deal | no |
快点，来不及了！
kuài diǎn, lái bu jí le
Hurry up — there's no time! (informal) — the final 了 is aspect le, not part of the idiom.
现在出发还来得及。
xiànzài chūfā hái lái de jí
If we leave now there's still time. (neutral) — the affirmative partner 来得及.
这里太热了，我受不了。
zhèlǐ tài rè le, wǒ shòu bu liǎo
It's too hot here — I can't stand it. (informal)
这点儿疼你受得了吗？
zhè diǎnr téng nǐ shòu de liǎo ma?
Can you handle this little bit of pain? (informal) — affirmative 受得了 in a question.
The 了 = liǎo trap
Several of these idioms end in the character 了, and here it is not the aspect particle le — it is the verb 了 "to finish / settle," read liǎo. So 受不了 is shòu bu liǎo, not shòu bu le; likewise 大不了 (dà bu liǎo) and 免不了 (miǎn bu liǎo, "unavoidable"). Read it le and a native speaker will hear something odd. The one place 了 is the aspect le is a trailing sentence particle, as in 来不及了 — there the idiom 来不及 is complete and the le is separate.
输了也没关系，大不了重来一次。
shū le yě méi guānxi, dà bu liǎo chóng lái yí cì
Losing is fine too — at worst we just do it over. (informal) — 大不了 read dà bu liǎo.
这种事免不了，别太在意。
zhè zhǒng shì miǎn bu liǎo, bié tài zàiyì
This kind of thing is unavoidable — don't take it to heart. (neutral)
Negative-only idioms: 怪不得, 恨不得, 巴不得
Three very common idioms exist only in the negative — there is no ✗怪得得, ✗恨得得, or ✗巴得得. 怪不得 "no wonder" fronts a clause and delivers a sudden realization. 恨不得 "wish desperately one could" introduces an impossible or exaggerated wish. 巴不得 "can't wait for / only too glad" introduces something you would love to see happen. The last two look alike but differ in tone: 恨不得 is your own frustrated yearning; 巴不得 is eager, sometimes gleeful, willingness.
怪不得他没来，原来生病了。
guài bu de tā méi lái, yuánlái shēngbìng le
No wonder he didn't come — turns out he's sick. (informal) — 怪不得 fronts the clause.
我恨不得马上飞回家。
wǒ hèn bu de mǎshàng fēi huí jiā
I wish I could fly home right this second. (informal) — an impossible, heartfelt wish.
他巴不得你早点走。
tā bā bu de nǐ zǎo diǎn zǒu
He'd be only too glad for you to leave early. (informal) — eager wish, slightly pointed.
他一个人把三个孩子带大，真了不起。
tā yí ge rén bǎ sān ge háizi dài dà, zhēn liǎo bu qǐ
He raised three kids single-handedly — truly amazing. (neutral) — 了不起 is a compliment despite the 不.
Common Mistakes
1. Inventing an affirmative for a negative-only idiom. 怪不得 / 恨不得 / 巴不得 have no 得-partner.
❌ 我恨得得马上回家。
Incorrect — there is no 恨得得; the idiom only exists as 恨不得.
✅ 我恨不得马上回家。
wǒ hèn bu de mǎshàng huí jiā
I can't wait to get home right now.
2. Confusing 来不及 (no time) with 来不了 (can't make it). One is about time, the other about attendance.
❌ 时间太紧，我来不了做完。
Wrong — 来不了 means 'can't come'; for 'not enough time to' use 来不及.
✅ 时间太紧，我来不及做完。
shíjiān tài jǐn, wǒ lái bu jí zuò wán
Time's too tight — I can't finish it in time.
3. Putting 怪不得 in the wrong slot. It heads its clause; it does not sit after the subject like an adverb.
❌ 他怪不得迟到了，路上堵车。
Incorrect — 怪不得 fronts the clause: 怪不得他迟到了.
✅ 怪不得他迟到了，路上堵车。
guài bu de tā chídào le, lù shang dǔchē
No wonder he was late — there was traffic.
4. Swapping 大不了 (at worst) for 了不起 (amazing). They share characters but mean opposite things.
❌ 输了也没关系，了不起重来。
Wrong — 了不起 means 'amazing'; for 'at worst' use 大不了.
✅ 输了也没关系，大不了重来。
shū le yě méi guānxi, dà bu liǎo chóng lái
Losing's fine — at worst we start over.
Key Takeaways
- These are frozen potentials — learn them whole: 来不及, 受不了, 了不起, 怪不得, 恨不得, 巴不得, 大不了, 免不了.
- 怪不得, 恨不得, 巴不得 are negative-only — don't build a 得-affirmative for them.
- The tail 了 in 受不了 / 大不了 / 免不了 is the verb liǎo, not aspect le; a trailing le (来不及了) is separate.
- 了不起 carries a positive meaning ("amazing") despite the 不 — don't read it as negative.
- Keep near-twins apart: 来不及 (no time) vs 来不了 (can't attend); 大不了 (at worst) vs 了不起 (amazing).
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Start learning Chinese→Related Topics
- Potential 得了 / 不了 (liǎo)HSK 4 — 得了 / 不了 (de liǎo / bu liǎo) is the all-purpose potential complement meaning an action can or can't be carried through — 去不了 (can't make it), 吃不了 (can't manage it all), 受不了 (can't stand it). The 了 here is read liǎo 'bring off', not le.
- Potential with 起: Afford, Respect, 对不起HSK 4 — The potential built on 起 means 'measure up to a level': 买得起 / 买不起 'can / can't afford', 看得起 / 看不起 'respect / look down on', 对得起 / 对不起 'do right by / fail' — which is why the everyday 对不起 'sorry' is literally 'unable to face you rightly'.
- Potential Complements 可能补语HSK 3 — The potential complement bakes 'can / can't' into the verb–result unit by slipping 得 (de, able) or 不 (bu, unable) into the seam: 看得懂 'can understand' vs 看不懂 'can't understand', 吃得完 vs 吃不完 — inherent possibility, and the negative form does almost all the work.