だろう

verb

Volitional/conjectural form of だ (da). Used to present a supposition. / Volitional/conjectural form of だ (da). Indicates question.

明日は晴れるだろう。

It will probably be sunny tomorrow.

意味（1）

Volitional/conjectural form of だ (da). Used to present a supposition.

Kikai no koshō darō.It's probably a mechanical failure.

意味（2）

Volitional/conjectural form of だ (da). Indicates question.

Kinō okutta shashin wa mita darō.You saw the photo I sent you yesterday, right?