Fetching details from the dictionary...
seems; I think; I guess; I wonder; I hope
right?; don't you agree?; I thought you'd say that!
明日は晴れるだろう。
It will probably be sunny tomorrow.
彼はもう帰っただろうと思った。
I thought he had probably already gone home.
これは難しいだろうか。
I wonder if this is difficult.