Processing keyword: ～と思う (〜to omou)

Japanese Grammar Point: ～と思う (〜to omou)

1. Introduction

The Japanese grammar point ～と思う (〜とおもう) translates to "I think that..." or "I believe that..." in English. It's a fundamental expression used to convey thoughts, opinions, and beliefs about various topics. Mastering ～と思う allows you to express yourself more naturally and engage in deeper conversations in Japanese.

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2. Core Grammar Explanation

Meaning

• ～と思う (〜とおもう): To think that..., to feel that..., to believe that... This construction is used when stating your personal thoughts or opinions about something.

Structure

The basic structure is: [Plain Form] + と思う Where [Plain Form] can be:

• Verbs (plain form)
• い-adjectives
• な-adjectives + だ
• Nouns + だ

Formation Diagram

Type	Plain Form	+	と思う	Meaning
Verb	食べる	+	と思う	I think (someone) eats
い-Adjective	高い	+	と思う	I think it's expensive
な-Adjective	便利 だ	+	と思う	I think it's convenient
Noun	学生 だ	+	と思う	I think (someone) is a student
Note: For な-adjectives and nouns, you must include だ before と思う.

Detailed Explanation

1. Verbs Use the plain form of the verb (dictionary form for present/future; た-form for past).
   • 彼は来ると思う。
     • I think he will come.
   • 雨が降ったと思います。
     • I think it rained.
2. い-Adjectives Use the adjective as-is (since the plain form is the same as the dictionary form).
   • この本は面白いと思う。
     • I think this book is interesting.
3. な-Adjectives and Nouns Add だ before と思う to link the noun or な-adjective to the verb.
   • この町は静かだと思います。
     • I think this town is quiet.
   • 彼は先生だと思う。
     • I think he is a teacher.

Visual Aid

Here's a simple diagram representing the structure:

[Verb (plain form)] + と思う
[い-Adjective] + と思う
[な-Adjective/Noun] + だ + と思う

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3. Comparative Analysis

～と思う vs. ～と思っています

• ～と思う: Expresses a thought or opinion formed at the moment or a general belief.
  • 明日、雨が降ると思う。
    • I think it will rain tomorrow.
• ～と思っています: Indicates a thought or opinion that has been held for some time; a more continuous state.
  • 彼は日本に住みたいと思っています。
    • He has been thinking of wanting to live in Japan.

～と思う vs. ～と言う

• ～と思う: "I think that..." (expressing personal thoughts)
  • その映画は面白いと思う。
    • I think that movie is interesting.
• ～と言う: "They say that..." or "To say that..." (reporting speech)
  • 彼はその映画は面白いと言う。
    • He says that movie is interesting.

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4. Examples in Context

Formal Speech

1. この提案は良いと思います。
   • I think this proposal is good.
2. あの方は有名な先生だと思います。
   • I think that person is a famous teacher.

Informal Speech

1. 今日は暇だと思う。
   • I think I have free time today.
2. 彼はもう寝たと思う。
   • I think he already went to sleep.

Written Context

1. 環境保護は重要だと思います。
   • I think environmental protection is important.
2. 私は、この計画は成功すると思います。
   • I believe that this plan will succeed.

Spoken Conversations

1. 明日のパーティーに行くと思う？
   • Do you think you'll go to tomorrow's party?
2. 彼女は忙しいと思うよ。
   • I think she is busy.

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5. Cultural Notes

Cultural Relevance

In Japanese communication, it's common to soften statements to be more polite and less direct. Using ～と思う helps to express opinions modestly, which is appreciated in Japanese social norms.

• 直接的: これは間違いです。 (This is wrong.)
• やわらかく: これは間違いだと思います。 (I think this is wrong.) Expressing uncertainty or personal opinion avoids potentially offending others and shows humility.

Idiomatic Expressions

• そう思います。
  • I think so.
• 私もそう思います。
  • I think so too. These phrases are commonly used to agree with someone's opinion politely.

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6. Common Mistakes and Tips

Error Analysis

1. Using Polite Forms Before と思う
   • Incorrect: 寒いですと思う。
   • Correct: 寒いと思う。
   • Tip: Always use the plain form before と思う, not the polite 〜です／〜ます form.
2. Omitting だ with Nouns and な-Adjectives
   • Incorrect: 彼は学生と思う。
   • Correct: 彼は学生だと思う。
   • Tip: Remember to insert だ before と思う when using nouns and な-adjectives.

Learning Strategies

• Practice Forming Sentences: Create your own sentences using different verbs, adjectives, and nouns to become comfortable with the structure.
• Mnemonic Device: Think "Plain Form + と思う", and remember that だ acts as a bridge for nouns and な-adjectives.

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7. Summary and Review

Key Takeaways

• ～と思う is used to express thoughts and opinions, equivalent to "I think that..." in English.
• Always use the plain form before と思う.
• For nouns and な-adjectives, include だ before と思う.
• Using ～と思います adds politeness suitable for formal situations.

Quick Recap Quiz

1. How do you say "I think it's delicious" in Japanese?
   • Answer: おいしいと思う。
2. Which form should you use before と思う: polite form or plain form?
   • Answer: Plain form.
3. Correct the sentence: これは重要ですと思います。
   • Answer: これは重要だと思います。

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Feel free to apply ～と思う in your daily Japanese conversations to express your thoughts and opinions naturally!

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