Take a verb that already has a result glued to it — 看懂 (read-and-understand), 拿动 (lift-and-move), 买起 (buy-and-afford) — and wedge the particle 得 into the seam. You have just formed the potential complement: 看得懂 "can understand (by reading)," 拿得动 "can lift," 买得起 "can afford." The negative is beautifully simple: swap 得 for 不 — 看不懂 "can't understand," 买不起 "can't afford." This 得 is the same character as the degree 得 of 说得很好, but its job here is different: it marks capability baked into the verb-plus-result, and it is the everyday way Mandarin says "can" for achievability. For the complement side in full, see the potential complement overview.
The infix that means "can": V + 得 + result
Start from a resultative or directional compound — a verb fused to its outcome — and the potential is formed by infixing 得 (able) or 不 (unable) right at the join. English needs a separate modal ("can," "be able to"); Mandarin builds the ability straight into the verb.
| Base compound | Potential (can) | Negative (can't) | Meaning |
|---|---|---|---|
| 看懂 (understand) | 看得懂 | 看不懂 | can / can't understand (reading) |
| 听懂 (understand) | 听得懂 | 听不懂 | can / can't understand (hearing) |
| 拿动 (lift-move) | 拿得动 | 拿不动 | can / can't lift |
| 买起 (afford) | 买得起 | 买不起 | can / can't afford |
| 吃完 (finish eating) | 吃得完 | 吃不完 | can / can't finish |
| 进去 (go in) | 进得去 | 进不去 | can / can't get in |
这本书太难了，我看不懂。
zhè běn shū tài nán le, wǒ kàn bu dǒng
This book is too hard — I can't understand it. (informal) — 不 infixed between 看 and 懂.
这么贵的房子，我们买不起。
zhème guì de fángzi, wǒmen mǎi bu qǐ
A house this expensive — we can't afford it. (neutral) — 买不起 is the everyday 'can't afford'.
这个箱子太重，我一个人拿不动。
zhège xiāngzi tài zhòng, wǒ yí ge rén ná bu dòng
This box is too heavy — I can't lift it by myself. (informal) — 拿不动: unable to make it move.
The negative is 不, never 得不
Learners who know the degree complement sometimes try to negate the potential by adding 不 to the complement, producing 拿得不动. That is ungrammatical. In the potential, ability and inability are a *single either/or switch at the infix: 得 = yes, 不 = no. There is no "得不" combination, and 没 (the past-tense negator) doesn't belong here either.
你说得太快，我听不懂。
nǐ shuō de tài kuài, wǒ tīng bu dǒng
You speak too fast — I can't follow. (informal) — note both de's: degree 说得太快, then potential 听不懂.
今天的作业不太多，我做得完。
jīntiān de zuòyè bú tài duō, wǒ zuò de wán
Today's homework isn't too much — I can finish it. (informal) — affirmative 做得完 answering an implicit 'can you?'
门锁着呢，我们进不去。
mén suǒ zhe ne, wǒmen jìn bu qù
The door's locked — we can't get in. (informal) — potential with a directional result, 进不去.
Potential 得 vs degree 得: use the negative to tell them apart
Here is the genuinely hard part, and the brief promised honesty about it. Some strings are structurally ambiguous. 看得清楚 can mean either "can see it clearly" (potential) or "sees it clearly" (degree/manner), because 清楚 works both as a result and as a describing adjective. Context usually settles it — but the clean, reliable test is how you negate:
| Reading | Affirmative | Negative |
|---|---|---|
| Potential ("can see clearly") | 看得清楚 | 看不清楚 |
| Degree ("sees it clearly") | 看得清楚 | 看得不清楚 |
Potential negates by flipping 得→不 at the infix (看不清楚); degree negates by dropping 不 into the complement (看得不清楚). Once you internalize this, the ambiguity stops being frightening — you simply ask "if I made this negative, where would 不 go?"
你说吧，我听得见。
nǐ shuō ba, wǒ tīng de jiàn
Go ahead — I can hear you. (informal) — potential 听得见; the negative would be 听不见.
黑板上的字你看得清楚吗？
hēibǎn shang de zì nǐ kàn de qīngchu ma?
Can you see the words on the blackboard clearly? (neutral) — a question, so the potential 'can see' reading is natural.
The potential complement overlaps in meaning with the modal 能 (néng) "can." Often either works, but the potential complement is the more idiomatic choice for a physical or perceptual achievement (听得懂, 拿得动), while 能 leans toward permission and general possibility — compared side by side on the potential vs 能 page.
Common Mistakes
1. Writing 的 for 得. Only 得 forms the potential; 的 before a verb-result is simply wrong.
❌ 我听的懂中文。
Incorrect — the potential infix is 得, not 的: 听得懂.
✅ 我听得懂中文。
wǒ tīng de dǒng Zhōngwén
I can understand Chinese. — 得 infixed into 听懂.
2. Negating with 不 in front of the verb. The 不 goes at the infix, not before the whole verb.
❌ 这本书我不看得懂。
Incorrect — negate at the infix: 看不懂, not 不看得懂.
✅ 这本书我看不懂。
zhè běn shū wǒ kàn bu dǒng
I can't understand this book. — 不 replaces 得 between 看 and 懂.
3. Building the negative as 得不. Ability is one switch; there is no 得不 combination.
❌ 这个箱子我拿得不动。
Incorrect — potential negates as 拿不动, never 拿得不动.
✅ 这个箱子我拿不动。
zhège xiāngzi wǒ ná bu dòng
I can't lift this box. — 拿不动.
4. Using 没 to mean 'can't'. 没 negates a completed event (没看懂 = "didn't understand [that time]"), which is not the same as inability.
❌ 太贵了，我没买得起。
Incorrect — inability uses 不: 买不起; 没 would mean 'didn't buy'.
✅ 太贵了，我买不起。
tài guì le, wǒ mǎi bu qǐ
It's too expensive — I can't afford it. — 买不起.
Key Takeaways
- Infix 得 into a verb-result compound to mean can: 看得懂, 拿得动, 买得起.
- Swap 得 for 不 for can't: 看不懂, 买不起 — this negative is the form you'll hear most.
- The negative is a single infix switch: never 得不, never 没, never 不 in front of the verb.
- Potential 得 (听得懂 = "able to") and degree 得 (听得清楚 = "hears clearly") can look identical — tell them apart by where 不 lands: 听不懂 vs 听得不清楚.
- The potential complement rivals 能 as an everyday "can," and is the idiomatic choice for physical or perceptual achievement.
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Start learning Chinese→Related Topics
- 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.
- 得 for Degree & Manner ComplementsHSK 3 — 得 (de) is the structural particle that clips onto a verb or adjective and opens a complement evaluating the action — 跑得快 (runs fast), 说得很好 (speaks very well): it sits after the verb, before the description.
- Potential Complement vs 能: Two Kinds of 'Can'HSK 4 — The potential complement (听得懂, 进不去) says whether an action reaches its result; the modal 能 (néng) covers permission, circumstance, and general capacity. English 'can' blurs them — Chinese keeps 进不去 (physically can't get in) apart from 不能进去 (not allowed in).
- Choosing 的 / 得 / 地HSK 3 — The decision guide for the three de's. 的 goes before a noun (红的花), 得 after a verb before a complement (跑得快), 地 before a verb as a manner adverb (快乐地唱). One test settles it: look at what comes right after.