だろう
Casual “probably”
You’ll be able to guess about things casually, the way friends do in relaxed conversation.
この荷物は重いだろう。
kono nimotsu wa omoi darou.
What do you think this sentence means?
This luggage is probably heavy.
Make a plain or casual guess
だろう is a plain counterpart of でしょう. It can express probability or seek agreement, but it often sounds rougher or more assertive depending on speaker and context.
明日は雨だろう。
ashita wa ame darou.
It will probably rain tomorrow.
Verbs, adjectives, and nouns
Attach だろう to the plain form of verbs and adjectives, or directly to nouns.
明日は晴れるだろう。
ashita wa hareru darou.
It will probably be sunny tomorrow.
この道は長いだろう。
kono michi wa nagai darou.
This road is probably long.
ここは静かだろう。
koko wa shizuka darou.
It is probably quiet here.
彼は学生だろう。
kare wa gakusei darou.
He is probably a student.
でしょう vs だろう
Both hedge a statement into a guess. でしょう is the polite one; だろう is its plain twin, for friends and for thinking out loud.
Plain
明日は雨だろう。
ashita wa ame darou.
It will probably rain tomorrow.
Casual, and common in writing that addresses no one.
Polite
明日は雨でしょう。
ashita wa ame deshou.
It will probably rain tomorrow.
The same guess, addressed politely.
明日は雨が降るだろう。
ashita wa ame ga furu darou.
It will probably rain tomorrow.
このケーキは甘いだろう。
kono keeki wa amai darou.
This cake is probably sweet.
バスはもうすぐ来るだろう。
basu wa mou sugu kuru darou.
The bus will probably come soon.
10 more examples in the grammar path — free for a limited time.