Japanese JLPT Grammar Point
~だものだ (〜da mono da)

~だものだ (〜da mono da)

Short explanation:

Express the reason or cause, often used to justify something.

Formation:

Verb-casual + んだものだ, い-Adjective + んだものだ, な-Adjective + なんだものだ, Noun + なんだものだ

Examples:

疲れたんだものだから、休みたい。
Tsukareta n da mono da kara, yasumitai.
I want to rest because I'm tired.
お腹が空いたんだものだから、何か食べたい。
Onaka ga suita n da mono da kara, nanika tabetai.
I want to eat something because I'm hungry.
忙しいんだものだから、来られない。
Isogashii n da mono da kara, korarenai.
I can't come because I'm busy.
彼は親切なんだものだから、誰も彼が好きだ。
Kare wa shinsetsu na n da mono da kara, dare mo kare ga suki da.
Everyone likes him because he is kind.

Long explanation:

The ~だものだ grammar point is used to explain a reason or cause, often to justify a certain action, decision, or outcome. It is used in a subjective and explanatory tone, and can be translated as 'because' or 'since' in English. The formation varies depending on whether it is used with a verb, い-adjective, な-adjective, or noun.

Detailed Grammar notes:

Processing keyword: ~だものだ (〜da mono da)

Japanese Grammar Point: ~だものだ (〜da mono da)

~だものだ (〜da mono da)

1. Introduction

The grammar point ~だものだ (〜da mono da) is used in Japanese to reflect nostalgically on past habitual actions or to express general truths and emotional reflections. It adds an emotional tone to statements, often conveying sentiments like "used to" or emphasizing the naturalness of a situation.


2. Core Grammar Explanation

Meaning

  • Expressing Past Habits with Nostalgia: Indicates actions that were regularly performed in the past, with a sense of nostalgia or reminiscence.

  • Emphasizing General Truths or Feelings: Highlights general principles, natural occurrences, or strong feelings about something.

Structure

Formation Diagram

  1. For Past Habits:

    [Verb た-form] + ものだ
    
  2. For General Truths/Emphasis:

    [Verb Dictionary Form] + ものだ
    [い-adjective] + ものだ
    [な-adjective] + なものだ
    

Visual Aid: Formation Table

Usage Formation Example
Past Habitual Action Verb (た-form) + ものだ 遊んだものだ
General Truth/Emphasis (Verb) Verb (dictionary form) + ものだ 時間が経つものだ
General Truth (い-adjective) い-adjective + ものだ 嬉しいものだ
General Truth (な-adjective) な-adjective + なものだ 静かなものだ

3. Comparative Analysis

Comparison with Similar Grammar Points

  • ~たものだ vs. ~たことがある
    • ~たものだ: Emphasizes habitual actions in the past with a nostalgic feeling.

      • 昔はよく友達と遊んだものだ。
      • "I used to play with my friends a lot in the past."
    • ~たことがある: Indicates having experienced something at least once.

      • 富士山に登ったことがある。
      • "I have climbed Mount Fuji before."
  • ~ものだ vs. ~ものだから/~もので
    • ~ものだ: Expresses general truths or emotions.

      • 人生は短いものだ。
      • "Life is short."
    • ~ものだから/~もので: Used to give reasons or excuses.

      • 遅れてごめん。電車が遅れたものだから。
      • "Sorry I'm late. Because the train was delayed."

4. Examples in Context

Sentence Examples

Past Habitual Actions

  1. 子供の頃、よく公園で遊んだものだ。 Kodomo no koro, yoku kōen de asonda mono da. "I used to play in the park a lot when I was a child."
  2. 学生時代は毎日図書館に通ったものだ。 Gakusei jidai wa mainichi toshokan ni kayotta mono da. "In my student days, I used to go to the library every day."
  3. 昔はここに大きな木があったものだ。 Mukashi wa koko ni ōkina ki ga atta mono da. "There used to be a big tree here in the past."

Emphasizing General Truths or Emotions

  1. 時間が経つのは早いものだ。 Jikan ga tatsu no wa hayai mono da. "Time sure does pass quickly."
  2. 人生は何が起こるかわからないものだ。 Jinsei wa nani ga okoru ka wakaranai mono da. "Life is something where you never know what will happen."
  3. 自然の力は偉大なものだ。 Shizen no chikara wa idai na mono da. "The power of nature is something great."

5. Cultural Notes

Cultural Relevance

  • Reflection and Nostalgia: Japanese culture highly values reflection on past experiences. Using ~ものだ allows speakers to express a sense of nostalgia and appreciation for past times.

Levels of Politeness and Formality

  • Formality: While ~ものだ is relatively neutral, in casual speech, it may appear as ~もんだ.

    • 忙しいもんだね。
    • "We're sure busy, aren't we?"
  • Politeness: Can be made more polite by using ~ものです.

    • 時間が経つのは早いものです。
    • "Time sure does pass quickly."

Idiomatic Expressions

  • 男は黙っているものだ。 Otoko wa damatte iru mono da. "Men should keep silent." (An old-fashioned saying emphasizing taciturnity as a virtue.)
  • 約束は守るものだ。 Yakusoku wa mamoru mono da. "Promises should be kept."

6. Common Mistakes and Tips

Error Analysis

  • Mistake 1: Using ~ものだ with current actions.
    • Incorrect: 今、勉強するものだ。
    • Correct: 学生時代はよく勉強したものだ。 Explanation: ~ものだ should not be used for present actions; it's for past habitual actions or general truths.
  • Mistake 2: Confusing ~ものだ with giving reasons (~ものだから).
    • Incorrect: 遅れたものだ、電車が遅れて。
    • Correct: 遅れたのは電車が遅れたものだから。 Explanation: ~ものだから is used to provide reasons or excuses, not to express nostalgia or general truths.

Learning Strategies

  • Remember the Emotional Tone: Associate ~ものだ with feelings of nostalgia or strong emotions about general truths.
  • Practice with Personal Experiences: Create sentences about your own past habits to internalize the structure.
    • Example: 昔は朝早く起きたものだ。
    • "I used to wake up early in the morning."

7. Summary and Review

Key Takeaways

  • ~だものだ is used to express:
    • Nostalgic reflection on past habitual actions.
    • Emphasis on general truths or natural occurrences.
  • Formation:
    • Past habits: [Verb た-form] + ものだ
    • General truths: [Verb Dictionary Form/Adjective] + ものだ
  • Emotional Tone: Adds a sentimental or reflective tone to statements.

Quick Recap Quiz

  1. How do you form the past habitual action using ~ものだ? A) [Verb Dictionary Form] + ものだ
    B) [Verb た-form] + ものだ
    C) [Verb ない-form] + ものだ
  2. Translate to English: 学生時代はよく徹夜したものだ。
  3. Which of the following is NOT a correct usage of ~ものだ? A) 時間が経つのは早いものだ。
    B) 毎日運動するものだ。 (Talking about a current habit)
    C) 子供の頃、虫を集めたものだ。

Answers

  1. B) [Verb た-form] + ものだ
  2. "I used to stay up all night often during my student days."
  3. B)

By understanding and practicing ~だものだ, you can express nostalgic feelings and emphasize general truths in Japanese, adding depth and emotion to your language.

hanabira.org

Ace your Japanese JLPT N5-N1 preparation.

Disclaimer

Public Alpha version Open Source (GitHub). This site is currently undergoing active development. You may (will) encounter bugs, inconsistencies, or limited functionality. Lots of sentences might not sound natural. We are progressively addressing these issues with native speakers.


花びら散る

夢のような跡

朝露に

Copyright 2025 @hanabira.org