Saying “can”: 会, 能 and 可以

These three words are the single most reliable source of mistakes at this level, because English hides the difference behind one word, “can”. In Chinese each of them answers a different question.

会 answers “have I learned how?” It is the verb of acquired skills: 我会说汉语 “I can speak Chinese”, 我会开车, 他不会游泳. If a class, a teacher or years of practice were involved, the word is 会. (会 has a second job — predicting what will happen: 明天会下雨 “It’ll rain tomorrow” — and context keeps the two apart easily.)

能 answers “do the circumstances allow it?” The skill may well be there; what decides is time, health, permission or the physical situation: 我今天不能去，我生病了 “I can’t come today, I’m ill.” 能 also covers capacity: 他一次能吃三碗饭 “He can eat three bowls of rice in one go.” And when you ask someone for a favour, 能 is the natural word: 你能帮我一下吗？

可以 answers “is it allowed?” It is the word of rules, permission and suggestions: 这儿可以拍照吗？ “Can you take photos here?”, 你可以问老师 “You could ask the teacher.”

The overlap is in questions about permission, where 能 and 可以 are both fine: 我能进来吗？= 我可以进来吗？ The split reappears in the answer. A refusal is normally 不能 (“circumstances don’t allow it”), while 不可以 is a firm prohibition, close to “you may not”: 这儿不能抽烟 is the everyday sign wording.

Two habits fix most errors. First, a skill that was learned takes 会 and nothing else — 我可以说汉语 means “I’m allowed to speak Chinese”, which is rarely what you mean. Second, if something is blocking you today, the word is 能 — 我今天不会去 would claim you don’t know how to go. Short answers reuse the word from the question: 你会开车吗？——会。