Translation guide
The English copula negation 'is not' has no single direct equivalent in Japanese. The correct expression depends on what is being negated: a noun/adjective identity, a location, an action, or a state. This guide covers the most common patterns for learners.
Express that something is not a certain thing or does not have a certain quality, using a noun or na-adjective.
Standard negative form of the copula だ. Used in plain speech and writing. Attach directly to a noun or na-adjective stem.
Contracted, more casual form of ではない. Very common in everyday conversation.
That's not a book.
Polite form of ではない. Used in formal situations, with superiors, or in polite writing.
This is not a book.
Polite form of じゃない. Slightly less formal than ではありません but still polite.
That is not a book.
Express that something does not have a certain quality described by an i-adjective.
Replace the final い of an i-adjective with くない to make the negative plain form.
Express that something does not exist or is not located somewhere.
Negative form of いる, used for animate beings (people, animals). Plain form.
Express that an action is not performed or a state does not hold.
Plain negative form of verbs. Conjugate the verb to its negative stem and add ない.
I do not eat meat.
Express that something was not a certain way in the past.
Plain past negative of だ. Used for nouns and na-adjectives.
That was not a book.
English 'is not' changes form depending on what follows. In Japanese, the negative form attaches to the predicate (noun, adjective, verb) itself. There is no standalone word for 'is not'.
ではない is used in writing and formal speech. じゃない is the contracted form used in casual conversation. Both are plain forms; add です for politeness.
He's not a student.
This book is not expensive.
It is not cold today.
Polite negative form of i-adjectives. Replace い with くありません.
This book is not expensive.
Polite form using くない + です. Common in polite conversation.
This book is not expensive.
There is no one in the room.
Negative form of ある, used for inanimate objects and abstract things. Plain form.
There is no book on the desk.
Polite negative of いる.
The teacher is not in the classroom.
Polite negative of ある.
There is no pen here.
彼は来ない。
He is not coming.
Polite negative form of verbs. Replace ない with ません.
I do not eat meat.
Casual past negative of だ.
He was not a student.
Plain past negative of i-adjectives. Replace い with くなかった.
It was not cold yesterday.