Processing keyword: ～だろう (〜darou)

Japanese Grammar Point: ～だろう (〜darou)

1. Introduction

The grammar point ～だろう (〜darou) is a versatile expression in Japanese that conveys probability, conjecture, or seeks agreement similar to "probably," "I think," or "right?" in English. It is commonly used in both spoken and written Japanese, making it an essential grammar point for learners aiming to achieve fluency.

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2. Core Grammar Explanation

Meaning and Usage

～だろう is used to:

1. Express conjecture or probability about a situation.
   • "It will probably rain tomorrow."
2. Seek confirmation or agreement from the listener.
   • "You're coming to the party, right?"

Formation

The formation of ～だろう depends on the type of word it attaches to.

Formation Diagram

Verb Form	Example Verb	+ だろう	Example Sentence
Plain form verb	行く (iku)	行くだろう	明日、彼は行くだろう。
I-adjective	高い (takai)	高いだろう	これは高いだろう。
Na-adjective	静かだ (shizuka da)	静かだろう	あそこは静かだろう。
Noun + だ	学生だ (gakusei da)	学生だろう	彼は学生だろう。

Structure

• For Verbs and I-adjectives: [ Verb (Plain form) / I-adjective ] + だろう
• For Na-adjectives and Nouns: [ Noun / Na-adjective + だ ] + ろう

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3. Comparative Analysis

～でしょう (〜deshou) vs. ～だろう (〜darou)

Both ～だろう and ～でしょう express conjecture, but they differ in formality.

• ～でしょう (deshou): More formal, polite.
• ～だろう (darou): Less formal, casual, or masculine speech. | | Politeness Level | Conjecture | Seeking Confirmation |

|-------------|------------------|------------|----------------------| | だろう | Casual | Yes | Yes | | でしょう | Polite | Yes | Yes |

4. Examples in Context

Expressing Conjecture

1. 天気予報によると、明日は雨が降るだろう**。**
   • Tenki yohō ni yoru to, ashita wa ame ga furu darou.
   • According to the weather forecast, it will probably rain tomorrow.
2. 彼はもうすぐ来るだろう**。**
   • Kare wa mō sugu kuru darou.
   • He will probably come soon.

Seeking Confirmation

3. この映画は面白かっただろう**？**
   • Kono eiga wa omoshirokatta darou?
   • This movie was interesting, right?
4. あなたも参加するだろう**。**
   • Anata mo sanka suru darou.
   • You're joining as well, aren't you?

Varying Levels of Formality

5. 彼は学生だろうと思います。 (Casual within polite sentence)
   • Kare wa gakusei darou to omoimasu.
   • I think he is probably a student.
6. 彼女は来ないだろうね。 (Casual and seeking agreement)
   • Kanojo wa konai darou ne.
   • She probably won't come, right?

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5. Cultural Notes

Levels of Politeness

• ～だろう is considered casual and is often used in informal conversations.
• Using ～でしょう is more appropriate in formal settings or when speaking to someone of higher status.

Gender Usage

• ～だろう can be perceived as masculine speech.
• Females might opt for ～でしょう or adjust their speech depending on the context.

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6. Common Mistakes and Tips

Common Mistakes

1. Using ～だろう in Formal Situations
   • Incorrect: 先生も来る*だろう。*
   • Correct: 先生も来る*でしょう。*
2. Mixing up with ～かな (kana)
   • ～かな expresses wondering or uncertainty.
   • Example: 彼は来るかな。 (I wonder if he will come.)

Tips

• Remember the Politeness Level: Use ～でしょう for formal situations.
• Context Matters: Pay attention to the context to choose between expressing conjecture or seeking confirmation.

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7. Summary and Review

Key Takeaways

• ～だろう expresses conjecture or seeks confirmation.
• It is used in casual contexts and may sound masculine.
• For formal situations, use ～でしょう instead.

Quick Recap Quiz

1. How do you express "It will probably snow tomorrow" using ～だろう?
2. Which form is more polite: ～だろう or ～でしょう?
3. Is ～だろう appropriate to use when speaking with your boss?

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Answers

1. 明日は雪が降るだろう**。**
2. ～でしょう is more polite.
3. No, you should use ～でしょう in formal situations.

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