How do you say you don't know whether something will happen in Irish?
For instance, does

"Níl a fhios agam an dtiocfaidh sí." mean "I don't know whether she will come."?

... or do we need to use the subjunctive tense with this? For instance, "I don't know if she would come." Hmmm.

Question

How do you say you don't know whether something will happen in Irish?
For instance, does

"Níl a fhios agam an dtiocfaidh sí." mean "I don't know whether she will come."?

... or do we need to use the subjunctive tense with this? For instance, "I don't know if she would come." Hmmm.

Answer

The sentence you give, with the future tense, is correct.
The subjunctive is most often used with "go": Fan go dtaga sí (although the future would also be acceptable here).