Translation guide
The English phrase "not being" can express negation of existence, identity, or a state. In Japanese, this is typically expressed using the negative forms of だ (da), です (desu), ある (aru), or いる (iru), depending on what is being negated. The choice depends on whether you are negating a noun/adjective (copula), the existence of inanimate objects, or the existence of animate beings. Additionally, the phrase "not being" can appear in English as a gerund or participle, which often requires different Japanese constructions.
To say that something is not something else, or that a state does not hold. This is the most common use of 'not being' as a copula negation.
Plain negative form of the copula だ. Used in casual speech and writing. Attaches to nouns and na-adjectives.
彼は学生ではない。
He is not a student.
それは簡単ではない。
That is not easy.
Contracted form of ではない, very common in spoken Japanese. Same meaning but more casual.
彼は学生じゃない。
He is not a student.
それは簡単じゃない。
That is not easy.
Polite negative form of です. Used in formal situations.
彼は学生ではありません。
He is not a student.
Slightly less formal than ではありません, but still polite. Common in speech.
彼は学生じゃありません。
He is not a student.
To say that something does not exist (for inanimate objects, concepts, events).
To say that a person or animal is not present or does not exist.
When 'not being' is used as a gerund (e.g., 'Not being able to swim is frustrating') or a participle (e.g., 'Not being a native speaker, I made mistakes'), Japanese uses different constructions depending on the context.
Nominalizes a verb or adjective in the negative form to express 'not doing/being something'. Used for gerund-like meanings.
泳げないことは悔しい。
Not being able to swim is frustrating.
The て-form of the negative, used to connect clauses. Can express 'not being X, ...' as a reason or simultaneous state.
ネイティブじゃなくて、間違えた。
Not being a native speaker, I made mistakes.
Expresses 'because not being...', giving a reason.
学生ではないので、割引が使えない。
Not being a student, I can't use the discount.
English 'not being' is a combination of negation and the verb 'to be'. Japanese does not have a single word for this; you must choose the correct negative form based on what is being negated (identity, existence, etc.).
Use ない for inanimate objects and abstract concepts. Use いない for people and animals. Using ない for people is a common mistake.