Translation guide
The English prefix 're-' indicates doing something again. In Japanese, this is expressed through adverbs, auxiliary verbs, or the prefix 再 (sai). The most common and versatile way is using the adverb もう一度 (mou ichido) or the prefix 再〜 (sai-).
re- (prefix for verbs)
Attach to masu-stem: 書き直す (rewrite).
Expressing that an action is repeated or done again, without specifying a formal process.
Literally 'one more time'. This is the most common and natural way to say 'again' for everyday actions. It can be used with most verbs.
Please say it again.
I'll try again.
Means 'again' or 'once more'. Slightly more casual than もう一度. Often used in everyday speech.
A more formal or literary way to say 'again'. Often used in written language or formal speeches.
Expressing the idea of redoing an action, often with a sense of correction or repetition from the beginning.
Attached to the masu-stem of a verb, it means 'to redo' or 'to do over', often implying fixing or improving. Very common for actions like rewriting, rebuilding, etc.
I rewrote the report.
To rebuild a house.
Also means 'to redo', but often implies doing something again in return or repeatedly. It can be less about correction and more about repetition.
〜返す can also mean 'to do back' (retaliate), so context matters.
Prefix attached to Sino-Japanese nouns (often する verbs) to mean 're-'. Common in formal or technical contexts.
To reconfirm
Expressing the repetition of a state or event, often with nouns.
The most direct equivalent of the prefix 're-' for nouns of Chinese origin. Used in many compound words.
Re-election
Re-entry (to a country)
For nouns that don't combine with 再, you can use もう一度 with the verb する.
To hold an election again
Both mean 're-', but 〜直す often implies fixing or doing over from scratch, while 〜返す can imply repetition or doing back. For simple 'redo', 〜直す is safer.
書き直す (rewrite to correct) vs. 書き返す (write back)
再〜 is mainly for Sino-Japanese words. For native Japanese verbs, use 〜直す or adverbs like もう一度. Saying 再食べる is unnatural; use もう一度食べる or 食べ直す.
Please re-enter your password.
I will redo the assignment.
Let's meet again.
It started raining again.
再びお会いできる日を楽しみにしています。
I look forward to the day we can meet again.
やり返す
To do back (retaliate) / to redo
再利用
Reuse