Beginners in Chinese learn to say "I can" using 能 (Néng) or 可以 (Kěyǐ). But walk down a street in Beijing, and you won't hear people saying "I can't understand" as Wǒ bù néng dǒng.
You will hear: 听不懂 (Tīng bu dǒng).
This structure is called the Potential Complement. It creates a nuanced difference between "having permission/ability" and "the action yielding a result." Mastering this is the gateway to passing HSK 3 grammar sections and surviving real-life conversations.
In this guide, we break down the formula, the "Big 5" most common phrases, and the trap of confusing it with standard modal verbs.
The Core Concept: Action + Potential Result
The Potential Complement indicates whether an action can achieve a specific result.
The Structure
- Positive (Can): Verb + 得 (de) + Result
- Negative (Can't): Verb + 不 (bu) + Result
Example: Finishing a meal.
- Verb: 吃 (Chī - Eat)
- Result: 完 (Wán - Finish)
- Positive: 吃得完 (Able to finish it).
- Negative: 吃不完 (Unable to finish it - e.g., the portion is too big).
This grammar relies heavily on understanding basic Chinese Complement Structures. If you don't know your Results (Hao, Wan, Dong), you can't build the Potential.
1. The Confusion: "Bu Neng" vs. "Verb + Bu"
This is where 90% of students make mistakes.
- 能 (Néng) / 可以 (Kěyǐ): Focuses on Permission or Conditions.
- Sentence: 我今天不能去。 (I cannot go today - because I am busy/not allowed).
- Potential Complement: Focuses on the Successful Outcome of the verb itself.
- Sentence: 我去不了。 (I physically cannot make it - e.g., legs are broken, or transport failed).
HSK Tip: If you want to say "I don't understand (the language)," ALWAYS use the Potential Complement (听不懂). If you use Wo bu neng ting, it implies your ears are broken or headphones are forbidden!
2. Essential Vocabulary List: The "Big 5" Scenarios
You don't need to memorize every combination. Memorize these five categories, which cover 80% of daily HSK usage.
A. Intellectual Grasp (Understand)
- 听不懂 (Tīng bu dǒng): Can't understand (by listening).
- 看不懂 (Kàn bu dǒng): Can't understand (by reading).
- Note: Critical for the HSK Listening exam!
B. Completion (Finish)
- 做不完 (Zuò bu wán): Can't finish doing (e.g., too much homework).
- 喝不完 (Hē bu wán): Can't finish drinking.
C. Sensory Perception (Clear)
- 看不清 (Kàn bu qīng): Can't see clearly (Blurry).
- 听不清 (Tīng bu qīng): Can't hear clearly (Too noisy).
D. Financial Ability (Afford)
This is unique. We use the verb 起 (qǐ - to rise) to imply having the status/money to uphold something.
- 买不起 (Mǎi bu qǐ): Can't afford. (Common HSK 4 usage).
- Positive: 买得起 (Can afford).
E. Capacity (Space)
Used with 下 (xià - down). Can you put it down into the space?
- 坐不下 (Zuò bu xià): Can't sit down (Not enough seats).
- 吃不下 (Chī bu xià): Can't eat anymore (Stomach is full).
3. Grammar in HSK Contexts
Question Formation
How do you ask: "Can you understand?"
- Natural Way: 你听得懂吗？ (Nǐ tīng de dǒng ma?)
- Alternative: 你能不能听懂？ (Nǐ néng bu néng tīng dǒng?) - Also correct, emphasizing ability.
The "De" Particle Usage
Do not confuse the 得 (de) here with the "Possessive De" or "Manner De." This De links the verb to the result. If you are struggling with which De to use, review our guide on the Structural Particle De.
4. Cultural "Idioms" with Complements
The potential complement forms the basis of many cultural sayings. Using these shows advanced proficiency.
1. 吃得苦 (Chī de kǔ)
- Literal: Able to eat bitterness.
- Meaning: Endures hardship well.
- Usage: He is very hardworking (他很能吃苦). Note: In colloquial speech, this is often treated as a noun object, but it stems from the potential structure.
2. 对不起 (Duì bu qǐ)
- Literal: Face not up. (I cannot face you/match you).
- Meaning: Sorry.
- Wait, what? Yes! The most common Chinese phrase is actually a fossilized Potential Complement. You are literally saying, "My action lowers me such that I cannot rise to face you."
5. Avoiding Common Mistakes
Mistake 1: Adding "Le" to negatives.
- Wrong: 我听不懂了。
- Correct: 我听不懂。(It is a state, not a completed action).
- Exception: Unless describing a change: "Suddenly, I can't understand anymore." Then "Le" is okay at the end. See Mastering the Le Particle.
Mistake 2: Mixing Object placement.
- Wrong: 我看不懂中文书。
- Correct: Same. SVO + V-De-C structure works.
- Trap: If using "Ba" structure, potential complements cannot be used. You can't say Wo Ba Shu Kan Bu Dong. Potential is not "Disposal."
Summary Table: Pattern recognition
| Intent | Sentence Structure | HSK Level |
|---|---|---|
| Simple Ability | Subject + 会 + Verb | HSK 1 |
| Possibility (Maybe) | Subject + 可能 + Verb | HSK 2 |
| Constraint/Logic | Subject + 不能 + Verb | HSK 2 |
| Result Achievability | Subject + Verb + 不 + Result | HSK 3 |
Practice Drill
Translate these mental thoughts to fix the logic:
- Thinking: "I don't have enough money for this car." -> 我买不起 (Wo mai bu qi).
- Thinking: "This textbook is too difficult language." -> 我看不懂 (Wo kan bu dong).
- Thinking: "My stomach is too small for this pizza." -> 我吃不下 (Wo chi bu xia).
Conclusion
The Potential Complement is the difference between "Textbook Chinese" and "Real Life Chinese." It allows you to express frustration (Can't finish!), confusion (Can't understand!), and limitations (Can't afford!) with precision.
Next time you watch a movie and miss a line of dialogue, don't say Wo bu neng ting. Say confidently: "Ting bu dong!"