GRAMMAR DETAIL

～だろう

probably; will likely

Follows a plain form or noun to express the speaker's prediction or a judgment considered highly likely.

Examples

明日は気温が下がるだろう。

The temperature will probably drop tomorrow.

この速さなら、予定より早く駅に着くだろう。

At this rate, we will probably reach the station earlier than planned.

この雲なら午後には雨が降るだろう。

With clouds like these, it will probably rain this afternoon.

Structure: A plain verb, plain i-adjective, noun, or na-adjective stem takes だろう.
Basic usage: 明日は気温が下がるだろう。 expresses the speaker's prediction that the temperature will drop.

Forms after nouns
- Attach it as in 雨だろう and 静かだろう. Polite speech uses でしょう, as in 雨でしょう.
The time being inferred
- もう着いただろう expresses the inference that arrival has already taken place. だろう itself is not a fixed future tense.