“でしょ(う)” is an auxiliary verb and a polite way of saying “だろう“. It has two meanings.
The first is “I think“. It is used to describe something that is unclear or unfamiliar. However, it is often used when you think it is certain regardless of whether you have particular information or evidence.
The second is “isn't it?“. It is used to get other people’s empathy.
- Meg: I like this dress. I think it’s appropriate to wear for my friend’s wedding party. What do you think?
この服いいな。友達の結婚パーティーにちょうどいいでしょ? - Tom: You should try it on.
着てみなよ。 - Meg: All right. (She is trying on the dress.) How do I look?
うん。どう?似合う? - Tom: That outfit really suits you!
すごく似合っている! - Meg: You think so too!
(そう)でしょ!
- Amy: Your dog is so adorable!
可愛い! - Meg: I know, right! I’m going to take the dog for a walk this evening.
(そう)でしょ!夕方散歩に連れて行くんだ。 - Amy: But look! It looks like it’s going to rain, right?
でも、(外を)見て!雨がふりそう、でしょ? - Meg: Yeah. Hmm, if he couldn’t go for a walk, he would be bored at home.
うん。あー、散歩に行けなかったら、家で退屈するだろうなぁ(orでしょうね)。
- Ken: I don’t know what to do if I can’t be a manager this year. I wonder if I should start thinking about changing jobs.
今年マネージャーになれなかったら、どうすればいんだろう。転職を考え始めようかな。 - Leo: Hey, I’m sure that you’ll get promoted because you have succeeded in completing the big project.
ねー、大きなプロジェクトを成功させたんだから、昇進できるでしょう(orだろう)。 - Ken: I like my job, but you know I’m not the person who can be a leader.
この仕事が好きだけど、僕はリーダーに向いてないでしょ(orだろう)!?