Potential Complement (得了/不了)

Potential complements answer the question: "Can the action achieve this result?" They are formed by inserting 得 (positive) or 不 (negative) between a verb and its resultative or directional complement. For example, 看见 (see = look + perceive) becomes 看得见 (can see) or 看不见 (cannot see).

This is different from using 能 or 可以. Those express permission or general ability, while potential complements express whether a specific result is achievable given the circumstances. Compare: 我能吃辣的 (I can eat spicy food — I have the ability) vs. 这个太辣了，我吃不了 (This is too spicy, I can't eat it — the result of eating it is not achievable for me).

The most common potential complements pair a verb with 了 (liǎo, meaning "to finish/manage"): 做得了 (can manage to do), 做不了 (cannot manage to do). Others use resultative complements: 听得懂 (can understand by listening), 听不懂 (cannot understand), 看得清楚 (can see clearly), 看不清楚 (cannot see clearly).

To form a question, add 吗 at the end: 你看得见吗？ Or use the positive-negative pattern: 你看得见看不见？ Potential complements are extremely common in daily Chinese and mastering them will make your speech sound much more natural.