How do you know when 会 means will and when it means can?
The sentence was 你会唱英语歌吗 and I put "Will you sing English songs" And it was wrong and the correct answer is "Can you sing English songs?"
It's hard to tell, I know. Usually, it depends on the situation. However, the usual definition is "can" because it sounds chunky in Chinese if you were for it to mean Will you sing English Songs. As a native speaker, I would say "唱个英文歌吧". I don't know, it depends how much practice you've had with Chinese speaking people. When I saw the sentence, I immediately knew it meant "Can you sing English songs?"
I hope this helped you, good luck!