があるだろうか

is there?

→ が

phrase Rare #32,544

is there? Used to ask whether something exists or might happen. Often conveys doubt or a rhetorical question, and can also mean “could there be?” depending on context.

JA: この計画に何か問題があるだろうか。

EN: Could there be any problems with this plan?

失明すること以上に大きな不幸があるだろうか。

Is there any greater misfortune than going blind?

彼がそんなことを言ったはずがあるだろうか。

There's no way he would have said such a thing.

今彼を説得して何か益があるだろうか。

Would there be any point in trying to persuade him now?

近い将来、地震があるだろうか。

Will there be an earthquake in the near future?