Translation guide
The English word "twice" means two times. In Japanese, the most common way to express this is with the counter 二回 (にかい), but other expressions exist depending on context, such as doubling or doing something again.
Expressing that an action or event occurs two times.
The standard counter for occurrences. Use with a verb to say 'do something twice'.
週に二回ジムに行きます。
I go to the gym twice a week.
I've seen that movie twice.
Similar to 二回, but slightly more formal or literary. Often used in set phrases.
二度とそんなことをしないでください。
Please don't do that ever again. (lit. 'don't do that twice')
Expressing that something is twice as much or twice the amount.
Means 'double' or 'twice as much'. Used for quantities, sizes, etc.
彼は私の二倍の給料をもらっている。
He earns twice my salary.
この部屋はあの部屋の二倍の広さです。
This room is twice as large as that one.
Expressing that something is done again, or for a second time.
Literally 'one more time', but often used where English would say 'twice' in the sense of 'a second time'.
もう一度言ってください。
Please say it again (a second time).
Formal way to say 'again' or 'a second time'. Common in business or official contexts.
再度ご確認ください。
Please check again (a second time).
Expressing frequency over a time period.
Pattern: time period + に + 二回. E.g., 一日に二回 (twice a day).
一日に二回歯を磨きます。
I brush my teeth twice a day.
Both mean 'twice', but 二回 is more common in everyday speech. 二度 is often used in negative sentences like 二度と〜ない (never again).
When 'twice' means 'double the amount', use 二倍, not 二回. Saying 二回の給料 would mean 'salary of two times' (as in occurrences), which is unnatural.
日本に二回行ったことがあります。
I've been to Japan twice.
これはあれの二倍の値段です。
This costs twice as much as that.