再び・二度|ふたたびfutatabi[0]heiban (flat)

1. adverbagain; once more; a second time
   そのようなことが再ふたたび起おこりうるだろうか。↗

   Can such a thing happen again?

• SynonymまたNeutralThe most common everyday word for again, as in 「また来ます」; it also means 'also'. More casual than 「再び」, which is more formal.
• SynonymまたまたCasualColloquial: once again, often with surprise or exasperation, as in 「またまた失敗」. Unlike the neutral, written-leaning 「再び」.
• Related改めてあらためてNeutralDoing something again on another occasion, or feeling something anew, as in 「改めて連絡します」「改めて感じる」; stresses starting afresh.
• RelatedまたしてもNeutralOnce again, often with regret or resignation, as in 「またしても負けた」; used mostly for undesirable things happening again.
• Related重ねてかさねてWrittenWritten/formal prose: once more or repeatedly, often in earnest requests such as 「重ねてお願い申し上げます」.
• RelatedまたもやWrittenWritten/formal prose: once again, with surprise or exclamation, as in 「またもや遅刻」; found mainly in news and narration.
• RelatedまたもWrittenWritten/formal prose: once again, stronger in tone than 「また」; seen mostly in news headlines.
• Antonym初めてはじめてNeutralFor the first time; the antonym of 「再び」 in the first-time vs. again contrast.

For 'again', 「また」 is the everyday choice and 「再び」 the more written, formal one. Use 「またしても」 or 「またもや」 when something bad happens yet again, and 「改めて」 for redoing something on another occasion.

Usage comparisons are AI-assisted and cross-checked by multiple models; for study reference only

1. 二に回かい。同おなじことが繰り返くりかえしなされるときの二に番目ばんめの回かい。