**** My answer - Almost same meaning. - でしょう：feminine or formal（ていねい） - だろう：masculine and （ちょっと乱暴） **** Reason: でしょう = でせう = でせむ = でせ＋む　（でせ　＜　未然形 of です） だろう　＝　であろう　＝　であら＋む　（であら ＜　未然形 of である） ※ む： a particle to indicate "guess", "will" The difference lies in root, です or である and "です" and "である" share almost same meaing and are interexchangeable. That means the difference comes down to nuance. である is more masculine (= 男っぽい　or オッサンくさい) than です。 Thisi is the diffrenece between でしょう and である *** Examples OK:どう、あたしって可愛いでしょう？　（Look, I am cute, you think so, don't you?) NG:どう、あたしって可愛いだろう？ ↑ not sound feminine OK：どうだい、オレってカッコイイだろう？ (Look, I am cool, you think so, don't you ?) NG：どうだい、オレってカッコイイでしょう？ ↑ not sound masculine , but unconfident OK: あの映画、おもしろかったでしょう？ (Both man and woman say this. Rather formally, because でしょう comes from です) OK: あの映画、おもしろかっただろう？ （Only man says this. not sound formally, because だろう comes from である)

Im female japanese I never use "だろう"alone Yes its more casual and it sounds like more male people talk I will use "だろうね" though 明日は雨だろう 明日は雨でしょう 明日は雨だろうね Every sentence has same meaning But でしょう is better for anyone Japanese use だろう、だろうねfor close friends or family でしょう is polite way to say だろう

でしょう is formal and respectful form of だろう. good luck!

Hi! 1. だろう is the non-polite form of でしょう。It means essentially the same thing as でしょう except that it sounds more masculine and is used mostly by males. 2. When でしょう is used in questions, it makes them sound more polite. Example: "What is it?" --> 何でしょうか。 3. でしょう can also be used to express various degrees of certainty, by means of (may). Example: "This medicine may be good" --> この薬がいいでしょう。 4. だろう can be seen in sentences just like the one we've just mentioned. Example: この薬がいいだろう。Or "Probably sleeping already." もう寝ているだろう。Or "I think Mr. Tanaka won't come today" --> きょう田中さんは来ないだろうと思います。In such sentences like the last one, you can't used でしょう because と must be preceded by a non-polite form. 5. Since people tend to be more assertive in casual situations, でしょう has a much stronger flavor often sounding more like, "See, I told you so!". Example: だから、時間がないって言ったでしょう！"That's why I told you there was no time!" Hope this helps.

My understanding is that でしょう and　だろう have the same meaning, but だろう is more casual and masculine.