An Easy Guide to だろう? (Darou)

Happy Sunday Japanophiles, herewith the 30th issue of the Hai Japan Newsletter — your Weekly Dose of Japan!

Today, we’re simply going through some grammar:

What Is だろう? (Darou)

だろう (darou) is often translated as "probably," "I assume," or "I believe."

It is used when you're making a guess or speculation based on your understanding of something.

When to Use だろう (Darou)

- Uncertainty: だろう (darou) is used when you're fairly sure about something, but not 100% certain. It shows that you have a reason for your guess, but you might not always say what that reason is.

For example:

- コウイチは金持ちだろう。 (Kouichi wa kanemochi darou.)

- "I believe Koichi is rich."

Here, you're saying you think Koichi is rich, maybe because he has a fancy car or a private helicopter, but you're not completely sure.

だろう (Darou) Comes From だ (Da)

だろう (darou) is a form of だ (da), which means "is" in Japanese. When you use だろう (darou), it has a more assertive or strong tone, especially in conversation.

In writing, it’s more about showing speculation.

Example in conversation:

- A: どのチームが優勝すると思う？ (Dono chiimu ga yuushou suru to omou?)

- "Which team do you think will win?"

- B: ジャイアンツだろうね。 (Jaiantsu darou ne.)

- "I assume it will be the Giants."

Here, B is guessing that the Giants will win, maybe because they are a strong team.

How to Use だろう (Darou) in Sentences

You can use だろう (darou) after nouns, adjectives, and verbs in both positive and negative sentences.

Nouns + だろう (Darou)

- 彼は歌手だろう。 (Kare wa kashu darou.)

- "I assume he is a singer."

- 彼は歌手じゃないだろう。 (Kare wa kashu janai darou.)

- "I assume he is not a singer."

Adjectives + だろう (Darou)

- きれいだろう。 (Kirei darou.)

- "I assume it is clean."

- きれいじゃないだろう。 (Kirei janai darou.)

- "I assume it is not clean."

Verbs + だろう (Darou)

- 彼は会社を休むだろう。 (Kare wa kaisha o yasumu darou.)

- "I assume he will take a day off."

- 彼は会社を休まないだろう。 (Kare wa kaisha o yasumanai darou.)

- "I assume he won't take a day off."

Speculating About the Future

To talk about future events, just add a time word like 明日 (ashita – tomorrow) or 来週 (raishuu – next week):

- 明日は寒いだろう。 (Ashita wa samui darou.)

- "It will probably be cold tomorrow."

To talk about a current action, use the ている (te-iru) form of the verb:

- 彼は会社を休んでいるだろう。 (Kare wa kaisha o yasunde iru darou.)

- "I assume he is taking a day off."

For past events, change the verb to past tense, but leave だろう the same:

- 彼は会社を休んだだろう。 (Kare wa kaisha o yasunda darou.)

- "I'm pretty sure he took the day off."

Levels of Certainty with だろう (Darou)

You can change how confident you sound by using adverbs like 多分 (tabun – probably), きっと (kitto – definitely), or 恐らく (osoraku – maybe).

- 明日はきっと寒いだろう。 (Ashita wa kitto samui darou.)

- "It will definitely be cold tomorrow."

- 明日は多分寒いだろう。 (Ashita wa tabun samui darou.)

- "It will probably be cold tomorrow."

Important! You can't use lower-probability words like もしかしたら (moshika shitara – maybe) with だろう, because they don't match the level of certainty だろう (darou) carries. For example:

- ❌ 彼はもしかしたら歌手だろう。 (Kare wa moshika shitara kashu darou.)

- This sentence doesn't work.

だろう for Seeking Confirmation

You can also use だろう (darou) to ask for confirmation or agreement. For example:

- 僕のプリン、食べただろう。 (Boku no purin, tabeta darou.)

- "You ate my pudding, right?"

Here, you're pretty sure they ate it, but you're asking to confirm.

This usage is more common in spoken Japanese, and when used this way, だろう (darou) often becomes だろ (daro), which has a stronger, more masculine tone:

- 僕の彼女、可愛いだろ。 (Boku no kanojo, kawaii daro.)

- "My girlfriend is cute, right?"

だろう for Asking Information

When asking for information, you can use だろ (darou) with question words like なん (nan – what), だれ (dare – who), どこ (doko – where), and いつ (itsu – when).

It doesn't sound as masculine in these cases.

- あれ、なんだろう？ (Are, nan darou?)

- "What do you think that is?"

- コウイチはどこだろう？ (Kouichi wa doko darou?)

- "I wonder where Koichi is."

You might use these questions when you're thinking out loud, wondering to yourself.

Summary

- だろう (darou) is used to express a guess or speculation.

- It can be used with nouns, adjectives, and verbs.

- You can adjust the certainty by using adverbs like きっと (kitto – definitely) or 多分 (tabun – probably).

- だろ (daro) can be used to seek confirmation or ask for information.

That’s all folks!

Let me know if you enjoyed this simple grammar run-through :)

Have a great Sunday!