Translation guide
The English phrase "if not" is used in several distinct ways: to introduce a negative condition, to suggest a possible alternative, or to express a degree of something. This guide covers the most common Japanese equivalents for each use.
To express 'if something is not the case' or 'unless'.
The standard conditional form for negative verbs and adjectives. Attach to the negative stem (nai-form without ない).
If you don't hurry, you'll be late.
To introduce a possible alternative, often meaning 'or perhaps' or 'or even'.
To express that something is at least a certain degree, or possibly more. Often used with adjectives.
Means 'even if not...', 'if not...'. Used to concede a point while still asserting something.
While もし can be used with negative conditionals, it is often omitted in natural Japanese. Overusing もし can sound unnatural or overly formal.
If you don't hurry, you'll be late.
安くなければ買いません。
If it's not cheap, I won't buy it.
A more casual conditional, often implying obligation or negative consequence. Used in spoken Japanese.
If we don't go soon, we won't make it.
Similar to ～なければ, but slightly more formal or emphatic. Often used in writing.
If you don't have permission, you cannot enter.
Literally 'if not, it won't do', used to express 'must' or 'have to'. This is a fixed phrase for obligation, not a direct conditional.
I have to do my homework.
Used to present an alternative possibility. Can be translated as 'or', 'or perhaps', 'if not'.
He might be a doctor, or perhaps a lawyer.
Used in questions to offer alternatives. More direct than あるいは.
Will you have coffee, or (if not) tea?
Formal alternative to あるいは, often used in legal or official contexts.
Please sign by yourself or (if not) by your representative.
If not perfect, it's still a pretty good result.
Literally 'even if it doesn't go as far as...', used to say 'if not X, at least Y'.
If not a beauty, she at least has charm.
Means 'rather', 'if anything'. Used to correct or emphasize a statement.
He's not so much sad as angry, if not angry.