も同然だ means just like; same as; practically equivalent to. It is a JLPT N1 Japanese grammar pattern used to assert that a situation is essentially no different from another, often with emotional weight or judgment.
This grammar point appears in both writing and speech, especially when you want to emphasize that something is so close to another thing that the difference hardly matters. If you need to call something “as good as,” “tantamount to,” or “practically the same as,” も同然だ is a versatile and natural choice.
What does も同然だ mean?
Use も同然だ when you want to equate one thing with another, not literally but in practical effect. The speaker is saying “for all intents and purposes, it’s the same as X.”
Natural translations include:
- just like ~
- same as ~
- as good as ~
- practically equivalent to ~
The best translation depends on tone. In English you might say “he’s as good as dead,” or “that’s just stealing.”
How to form も同然だ
Examples of the pattern:
- 泥棒 + も同然だ → 泥棒も同然だ
- 盗んだ + も同然だ → 盗んだも同然だ
- 壊れた + も同然だ → 壊れたも同然だ
The form before the pattern is direct: either a noun (no particle needed) or a plain-form verb that describes the state or action. Avoid inserting です or polite endings before も同然だ; it attaches directly.
When is も同然だ used?
Use も同然だ in situations like:
- equating an action to a crime, mistake, or failure
- describing something that is so ruined, useless, or changed that it might as well be something else
- delivering a strong, subjective judgment about a situation
Tone and register:
- neutral to slightly formal; sounds natural in both conversation and writing
- often carries a negative or critical overtone, but can be used positively (勝ったも同然だ = as good as won)
- Common in essays, editorials, fiction, and JLPT N1 reading sections
も同然だ example sentences
After reading each sentence, notice how も同然だ collapses the distance between what something is and what it might as well be. That subjective leap is the core of this pattern.
Nuance of も同然だ
The key nuance is subjective equivalence — the speaker declares that one thing is so close to another that the boundary is irrelevant.
This matters because learners sometimes confuse it with more objective expressions like に等しい. With も同然だ, you are adding your personal assessment — you are telling the listener how to interpret the situation.
For example:
- 盗んだも同然だ says “it’s stealing in my eyes,” not “this meets the legal definition of theft.”
- 死んだも同然だ might be said about a hopeless case, not a medical pronouncement.
も同然だ vs に等しい
Both も同然だ and に等しい can express that two things are alike, but they differ in objectivity and emotional charge.
If both translations seem possible, check the speaker’s stance. も同然だ puts the speaker’s evaluation front and center; に等しい just reports a fact.
Common mistakes with も同然だ
Watch out for these mistakes:
A good self-check: after writing a sentence with も同然だ, try replacing it with に等しい. If the sentence becomes a dry fact and loses the emotional punch, you’ve used も同然だ correctly.
Is も同然だ on the JLPT?
Yes, も同然だ is a JLPT N1 grammar point. It’s a classic example of advanced judgment patterns that appear in the reading comprehension and listening sections.
- Recognize it in complex sentences and infer the speaker’s attitude
- Understand its nuance of subjective equivalence, not literal equality
- Use it in a short original sentence when necessary (e.g., writing section)
For test preparation, practice with sentences where the grammar point follows a negative action or an extreme state. JLPT N1 questions often test whether you catch the emotional weight behind 同然 and can distinguish it from 等しい or 当然.
Practice questions for も同然だ
Focus on attaching a noun or a plain past verb directly, then add context to sharpen the judgment.
Learning path for も同然だ
To learn も同然だ efficiently, start with its mechanical attachment, then internalize its subjective flavor, and finally use it in your own opinions.
Related grammar to review next
- もさることながら — also connects two points of similar weight (often “not only that, but also”).
- もしないで — involves a negated action that leads to an outcome; useful when you want to say “without even doing X.”
- めく — shows that something resembles something else or takes on a certain quality (“to look like,” “to have an air of”).
- まるっきり — expresses total negation or absoluteness; pairs well with negative states.
Learn も同然だ with Hane
If you want to review も同然だ together with the related patterns above, Hane helps you practice Japanese in short, focused sessions.
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FAQ about も同然だ
What does も同然だ (mo douzen da) mean in Japanese?
も同然だ (mo douzen da) means “just like; same as”. It is JLPT N1 grammar. Use も同然だ when you want to equate one thing with another, not literally but in practical effect. The speaker is saying "for all intents and purposes, it’s the same as X.
How do you form も同然だ (mo douzen da)?
Noun + も同然だ Verb (plain form, often past) + も同然だ
What is the difference between も同然だ and に等しい?
も同然だ: subjective, practical equivalence. に等しい: objective, literal equality.
What is an example sentence with も同然だ (mo douzen da)?
泥棒も同然だ。 — He’s just like a thief.