〜でしょう / 〜だろう
JLPT N4:probably
Gives a guess you feel fairly sure of: "probably", "I suppose". でしょう is polite; だろう is plain.
How to form it
- Put the plain form before でしょう or だろう: 晴れるでしょう, 寝ただろう.
- Nouns and な-adjectives take it directly, with no だ: 雨でしょう, 静かだろう.
- たぶん or きっと often comes earlier in the sentence: たぶん来るでしょう.
Examples
明日は晴れるでしょう。
It will probably be sunny tomorrow.
彼はもう寝ただろう。
He's probably asleep by now.
Notes
- With rising intonation, でしょう asks for agreement: 疲れたでしょう？ (you must be tired, right?).
Similar meaning
- 〜かもしれないmight / maybe
"Might": less certain.
- 〜はずだshould be (expected)
"Should be": a conclusion from what you know.