Translation guide
A guide to expressing the conditional 'if so' in Japanese, covering common patterns for confirming, responding, and linking to previous statements.
The speaker asks or states what follows if the preceding statement is true, often in conversation.
A very common and natural way to say 'if so' or 'in that case', used in both casual and polite speech. It directly refers to what was just said.
A: 明日は雨だって。B: それなら、傘を持っていくよ。
A: They say it'll rain tomorrow. B: If so, I'll take an umbrella.
A casual, conversational way to say 'if so' or 'then'. Often used in spoken Japanese.
A: この店、閉まってるよ。B: だったら、別の店に行こう。
A: This shop is closed. B: If so, let's go to another shop.
Literally 'if that is so', slightly more formal than それなら. Used when confirming a condition.
そうなら、早く知らせてください。
If so, please let me know quickly.
Polite version of そうなら, suitable for formal situations or when speaking to superiors.
そうでしたら、こちらにおかけください。
If so, please have a seat here.
The speaker presents a consequence or action based on a hypothetical situation that may or may not be true.
Explicitly marks the condition as hypothetical with もし, meaning 'if that is the case'. Used when the truth is uncertain.
もしそうなら、大変なことだ。
If so, it's a serious matter.
A more formal or written pattern meaning 'if that is the case', often used in logical reasoning.
彼が犯人だとすれば、動機は何だろう。
If he is the culprit, what would the motive be?
A stiff, literary, or formal pattern. Rare in everyday speech.
それが事実であるならば、対策を講じなければならない。
If that is true, we must take measures.
The speaker asks a follow-up question or makes a request that depends on the previous statement being true.
Use それなら to naturally lead into a question that assumes the previous statement.
A: 明日は休みだよ。B: それなら、映画を見に行かない？
A: Tomorrow is a day off. B: If so, why don't we go see a movie?
Casual version for follow-up questions.
A: このケーキ、おいしくない？B: だったら、なんで食べてるの？
A: This cake isn't good, is it? B: If so, why are you eating it?
それなら is the most neutral and widely used. だったら is more casual and conversational. そうなら is slightly more formal and often used in written or polite contexts. そうでしたら is the polite version.
Direct translations like 'もしそう' without a conditional ending are incomplete. Always use a full pattern like それなら or もしそうなら. Also, do not use もし alone to mean 'if so'.