Grammar JLPT Level N5 - Lesson 5

Structure of でしょう:

Tentative
Noun + でしょう
Verb + でしょう
Adjective + でしょう

Details about でしょう:

でしょう is a conjugated form of です, and can also be seen in the contracted form でしょ (more casual). でしょう is regularly translated to 'right?', or 'probably' in English. In a broader sense it just expresses an assertion about something (like です), that the speaker assumes the listener would probably agree with.

イタリアは良(よ)かったでしょう。
Italy was nice, right? (Has the nuance of 'I bet!)
今日(きょう)の昼(ひる)ごはんはハンバーガーでしょう。
Today's lunch is probably hamburgers, right?

In the above, we can see that, in both examples, the speaker is looking for confirmation that/affirming that the listener agrees with them.
As でしょう is a conjugation of です (the polite form of だ), it usually follows the plain form of words, rather than words using ～ます. However, in very formal situations, or older literature ～ますでしょう may be seen.

彼(かれ)も踊(おど)るでしょう。
He will probably dance too.
彼(かれ)も踊(おど)りますでしょう。
He will probably dance too.

でしょう

Usage Notes for でしょう:

Despite sounding relatively low confidence, using でしょう implies that the speaker has some form of information that makes them believe that the (A) statement is true.