ものではない

Shouldn't

Level 3Sounds Like monodehanai

ものではない is used to express that a certain action is socially unacceptable or against common sense. It focuses on universal rules rather than personal advice.

How It Works

1. Meaning and Nuance
ものではない translates to 'one shouldn't' or 'it is not proper to.' The implied subject is usually a universal 'people' or 'anyone,' rather than a specific individual. Unlike a direct command, it appeals to a higher standard of behavior or social norms. It carries a didactic (preachy) tone, suggesting that the behavior in question is simply 'not the way things are done' in a civilized society. Its positive counterpart is 〜ものだ (One should / It is common sense to...), which carries the same preachy tone.

2. Formation
It attaches to the Dictionary Form of a verb:

  • Verb (Dictionary Form) + ものではない
  • Verb (Dictionary Form) + ものではないのです (More explanatory)
  • Verb (Dictionary Form) + もんじゃない (Casual/Spoken)

3. Register and Usage
In formal writing or speeches, ものではない is used to state ethics. In daily life, the casual form もんじゃない is very common when parents scold children or when friends give stern advice based on common sense. Because of its preachy tone, you should avoid using it toward superiors, as it can sound arrogant.

4. Comparison: ものではない vs. 〜べきではない
Learners often confuse this pattern with 〜べきではない. While both can be used for general moral rules, 〜べきではない is based on the speaker's logical judgment or personal opinion and can also apply to specific, one-time situations. In contrast, ものではない is strictly for general, timeless social norms or common sense, and sounds more like a universal truth rather than a personal opinion.

5. Comparison: ものではない vs. 〜というものではない
While they look similar, 〜というものではない is used for partial negation ('It's not necessarily the case that...'). In contrast, ものではない is a moral prohibition ('One should not...'). Additionally, 〜というものではない can attach to nouns and adjectives, whereas ものではない only attaches to verbs when used as this specific moral prohibition pattern (literal phrases like 安いものではない 'It is not a cheap thing' are just regular noun modifications).

6. Important Distinction: Dictionary Form vs. Potential Forms
Be careful! When used with potential forms, the meaning changes completely.

  • Present Potential Form (Literal Use): Means 'It is not something that can be [verb]ed (easily).' Example: 簡単にできるものではない (It's not something that can be done easily).
  • Past Potential Form (Idiomatic Use): Means 'cannot possibly do' or 'is in no state to be [verb]ed.' Example: 食べられたものではない (It's so gross it's inedible) vs. 食べるものではない (One shouldn't eat [that]). Although it uses the past-tense form of a potential verb (〜た), the idiomatic grammar pattern 〜たものではない expresses a present state of absolute impossibility or unbearableness.

Examples (6)

  1. 人を外見で判断するものではない。

    One shouldn't judge people by their appearance.

    Word by Word: People (object) appearance by judge thing is not.

    This is a general moral principle applicable to everyone.

  2. 口の中に物を入れたまま、しゃべるもんじゃないよ。

    You shouldn't talk with your mouth full.

    Word by Word: Mouth inside in things put while, talk thing is not (particle).

    This uses the casual もんじゃない to correct someone's social etiquette.

  3. 目上の人にそんな言い方をするものではありません。

    It is not proper to speak to your superiors in that manner.

    Word by Word: Superiors to that kind of way of speaking (object) do thing is not (polite).

    This uses the polite form to state a rule regarding social hierarchy.

  4. 嘘をつくものではないと子供の時に教わった。

    I was taught as a child that one should not tell lies.

    Word by Word: Lies (object) tell thing is not that child time at was taught.

    Here, the pattern describes a universal moral lesson.

  5. そんなに簡単に諦めるもんじゃない。

    You shouldn't give up so easily.

    Word by Word: That easily give up thing is not.

    A common way to give stern encouragement based on what is considered 'right' behavior.

  6. この料理は辛すぎて、食べられたものではない。

    This food is so spicy it's inedible (cannot possibly be eaten).

    Word by Word: This food (topic) too spicy, could eat thing is not.

    This demonstrates the past potential form usage, where the meaning shifts from 'shouldn't' to 'impossible' or 'unbearable'.

Common Mistakes

  • Using it for specific, one-time personal advice.

    今夜のパーティーに行くものではないよ。
    今夜のパーティーには行かないほうがいいよ。

    ものではない is for universal rules or social common sense. For specific advice like 'You shouldn't go to the party tonight,' use ほうがいい instead.

  • Confusing the Dictionary Form with the Past Potential Form.

    そんなものを食べたものではない。
    そんなものを食べるものではない。

    食べたものではない is ungrammatical for this meaning. To say 'It was so bad it was inedible,' you must use the past potential form 食べられたものではない. To say 'You shouldn't eat that' as a general rule, you must use the dictionary form 食べる.

How It Connects

Tap a pattern to see what it builds on and what it leads to.

ものではないLevel 3Shouldn't

Learn This First

To understand 'ものではない', you first need to understand its affirmative counterpart 'ものだ', which expresses social expectations or general rules. Structurally, it combines a verb in the dictionary form with the nominalizer 'もの' followed by the negative copula 'ではない' to state that a certain action is socially or morally inappropriate.

Words in This Pattern

物では無い