How to Say “Can” and “Can’t” with 得 / 不 (Potential Complements)
To say whether an action can reach its result, Chinese slots 得 (can) or 不 (can’t) between the verb and its complement: Verb + 得/不 + Complement. 吃得完 / 吃不完 (“can / can’t finish”), 买得到 / 买不到 (“can / can’t get”), 看得清楚 / 看不清楚 (“can / can’t see clearly”). This is the general potential complement, built on the result and direction complements you already know.
Why this trips learners up
Chinese has a compact way to say whether an action can actually get there: take a verb and its complement, and drop 得 (can) or 不 (can’t) in the middle. The shape is Verb + 得 / 不 + Complement. 吃得完 = “can finish (eating)”, 吃不完 = “can’t finish”; 买得到 = “can get (buy)”, 买不到 = “can’t get”. One syllable in the middle flips the whole meaning.
This is called a potential complement, and it’s built on complements you already have. Result complements: 看懂 (understand) becomes 看得懂 / 看不懂, 做完 (finish) becomes 做得完 / 做不完, 看清楚 (see clearly) becomes 看得清楚 / 看不清楚. Direction complements do it too: 起来 (get up) becomes 起得来 / 起不来, 上去 (go up) becomes 上得去 / 上不去. Whatever the complement, the potential form just wedges 得 or 不 in front of it.
The object has two homes. It can follow the whole thing (你找得到我家吗？, “can you find my house?”; 我做不完作业, “I can’t finish the homework”), or it can be pulled to the front as a topic (这种老照片现在买不到了, “you can’t buy this kind of old photo anymore”). Both are natural; fronting the object is especially common when it’s long or already known.
The big trap for English, German, French, Spanish and Portuguese speakers is reaching for a “can” word. “I can’t finish these dishes” is 吃不完, not 不能吃完. Two things to hold onto: 得/不 is an infix that lives inside the verb+complement, never a modal in front of the verb (so 我做不完作业, never 我不做完作业); and it answers a different question from 能. The potential complement asks can the action reach its result (finish, arrive, see clearly, get up); 能 / 不能 covers permission and general possibility. One more limit: a negative potential complement can’t sit in a 把 sentence, since 把 spotlights an object fully dealt with. In everyday speech the negative (吃不完, 买不到, 听不懂) is far more common than the affirmative.
The structure
Colour key
Each colour marks one grammatical role — and the same colour means the same role on every page in the Lab.
Examples in context
Real-world sentences, easiest first. Toggle pinyin or the translation, tap any word to see its role, or play the audio.
Tap a word to see its grammatical role.
zhème duō cài 这么多菜 Object nǐ ，你 Subject chī 吃 Verb de 得 Function word wán 完 Complement ma 吗 Question
So much food, can you finish it? (吃得完, the affirmative 得).
wǒ 我 Subject jīntiān 今天 Time zuò 做 Verb bu 不 Negation wán 完 Complement zuòyè 作业 Object
I can’t finish the homework today (做不完, negative, object after the complement).
nǐ 你 Subject zhǎo 找 Verb de 得 Function word dào 到 Complement wǒ jiā 我家 Object ma 吗 Question
Can you find my house? (找得到, affirmative, object after 到).
zhè zhǒng lǎo zhàopiàn 这种老照片 Object xiànzài 现在 Time mǎi 买 Verb bu 不 Negation dào 到 Complement le 了 Function word
You can’t buy this kind of old photo anymore (买不到, the object fronted as topic).
tài lèi le 太累了 Other wǒ ，我 Subject zǎoshang liù diǎn 早上六点 Time qǐ 起 Verb bu 不 Negation lái 来 Complement
I’m too tired to get up at six (起不来, the potential form of a direction complement).
nǐ 你 Subject zuò hòumiàn 坐后面 Other kàn 看 Verb de 得 Function word qīngchu 清楚 Complement ma 吗 Question
Sitting at the back, can you see clearly? (看得清楚, an adjective-result complement).
zhège xiāngzi tài zhòng 这个箱子太重 Other wǒ ，我 Subject yí gè rén 一个人 Adverb bān 搬 Verb bu 不 Negation dòng 动 Complement
This box is too heavy, I can’t lift it on my own (搬不动).
zì dà yìdiǎn 字大一点 Other wǒ 我 Subject jiù 就 Adverb kàn 看 Verb de 得 Function word qīngchu 清楚 Complement tài xiǎo le ，太小了 Other jiù 就 Adverb kàn 看 Verb bu 不 Negation qīngchu 清楚 Complement
If the text is bigger I can see it clearly, if it’s too small I can’t (得清楚 vs 不清楚, side by side).
Common mistakes
Why it happens: Reaching the result is the potential complement, not 不能. “I can’t finish these dishes” is 吃不完, not 不能吃完. 不能 means “not allowed / not possible in general”; the “can’t manage to finish” sense lives in the 不 inside 吃不完.
Why it happens: The 不 is an infix: it sits between the verb and the complement (做不完), never in front of the verb. 不做完作业 negates the verb (“won’t finish”); the inability to reach the result has to sit right before 完.
Why it happens: A negative potential complement can’t appear in a 把 sentence. 把 spotlights an object being fully dealt with, so it clashes with “can’t finish it.” Drop 把 and topicalize the object: 这些菜我吃不完.
Compare & contrast
| Verb 得 / 不 Complement: can the result happen? | 能 / 不能 + Verb: allowed or possible in general? | The difference |
|---|---|---|
| 我搬不动这个箱子wǒ bān bu dòng zhège xiāngzi = “I can’t lift this box” (my strength can’t reach the result 动 → potential complement) | 我不能搬这个箱子wǒ bù néng bān zhège xiāngzi = “I’m not allowed to move this box” (external permission → 不能) | 我搬不动这个箱子 = “I can’t lift this box,” my strength can’t reach the result 动, so it’s the potential complement. 我不能搬这个箱子 = “I’m not allowed to move this box,” an external rule, so it’s 不能. Reaching the result versus having permission. |
| 这个字我写得出来zhège zì wǒ xiě de chūlái = “I can come up with this character” (I manage to recall and produce it → potential complement) | 这个字我能写zhège zì wǒ néng xiě = “I can write this character” (I have the general ability → 能) | 这个字我写得出来 = “I can come up with this character,” I manage to recall and produce it (得出来). 这个字我能写 = “I can write this character,” I have the general ability (能). Managing it in the moment versus general capability. |
Try it yourself
Say “I can’t lift this box.” Front the object, then put 不 between the verb and 动: 这个箱子我搬不动.
Related patterns
Quick reference card
How to Say “Can” and “Can’t” with 得 / 不 (Potential Complements) grammar.merrymandarin.com A pocket summary — print it and keep it by your desk.