English has one word, "can", but Chinese has three. 会 (huì) is for skills you have learned, 能 (néng) is for being able to do something in the situation, and 可以 (kěyǐ) is for permission. All three go straight before the verb, and all three are HSK 1 words.
Subject + 会 + verb (+ object).
Use 会 for things you had to learn: speaking a language, driving, cooking, writing characters. 我会说中文 means you know how to speak Chinese. 不会 means you never learned how.
会 has a second meaning: it says that something is likely to happen, a bit like "will" in English. You will hear it a lot when people talk about the weather or make guesses about the future. 不会 then means "won't" or "isn't going to".
能 is about whether you are able to do something at a given time: whether you are free, whether something works, or how much you can manage. It is less about learning and more about circumstances.
So someone who knows how to drive 会开车, but if they are too tired today, they 不能开车.
可以 is the usual word for asking for or giving permission: "may I...?", "you can...". 能 is also often used in questions like 我能……吗.
To say something is not allowed, 不能 is the most common choice. 不可以 is also correct but sounds firmer, like a rule or a parent talking to a child. When someone asks 可以吗, a short yes is 可以, and a short no is often 不行 (not OK).
Make all three negative with 不 before them: 不会 (bú huì), 不能, 不可以. Ask a yes/no question with 吗 at the end, or with verb-not-verb: 会不会, 能不能. To answer, just repeat the word: 会 or 不会, 能 or 不能.
The most common learner mistake is to use 可以 or 能 for a skill. For something you have learned, such as a language, 会 is the natural choice. 我可以说中文 sounds like "I'm allowed to speak Chinese" or "I can speak Chinese if you like", not a statement about what you have learned.
Practise this grammar point on paper: 20 exercises using only HSK 1 words, with an answer key on a separate page. Free to print and copy for your class.
Every example on this page uses only words up to HSK 1. Paste your own sentences into the level checker to see which words, if any, are above your level.