In Korean, the grammar structure (으)ㄹ 수 있다/없다 is used to express the ability or inability to do something.
The phrase translates literally as 'is it possible?' or 'is possibility existing?'
You can intensify the expression by adding 가 to it, thereby adding emphasis.
The structure (으)ㄹ 수 있다/없다 is a simple but effective way to express your capabilities or limitations in Korean.
By adding 가, you can further emphasize the strength of your statement.