Translation guide
The English word 'quick' covers speed, time, intelligence, and temperament. Japanese uses different words depending on the nuance.
Describing something that moves or happens at high speed.
The most common word for 'fast' or 'quick' in terms of speed. Used for vehicles, running, actions, etc.
彼は足が速い。
He is a quick runner.
この車はとても速い。
This car is very quick.
Emphasizes agility and nimbleness, often for physical movements or reflexes.
Formal or written term for 'swift' or 'prompt', often used in business or official contexts.
Means 'early' rather than 'fast', but can overlap when referring to quick timing. Often confused with 速い.
Do not use 早い for physical speed; it means 'early' in time.
Describing an action or process that is completed in a short duration.
Used when something is done quickly, without delay. Often overlaps with 'early'.
Adverb meaning 'immediately' or 'right away'. Very common for 'quickly' in the sense of 'without delay'.
すぐに戻ります。
I'll be back quickly.
Adverb meaning 'quickly' or 'without hesitation', often with a sense of briskness or impatience. Casual.
Describing a person who understands or learns things rapidly.
Literally 'head is good', meaning smart or quick-witted. Very common.
彼女は本当に頭がいい。
She is really quick-witted.
Means clever, smart, or quick-witted. Often used for children or animals.
利口な犬だ。
A quick (clever) dog.
Means 'sharp' or 'quick-witted', often describing someone's mind or judgment.
今日は頭が冴えている。
I'm quick-witted today.
Easily angered or irritable.
速い (hayai) is for physical speed (fast car, quick runner). 早い (hayai) is for time (early morning, quick reply). They are pronounced the same but written differently. In many contexts, 早い can be used for 'quick' in the sense of 'not taking much time'.
The loanword クイック (kuikku) is not commonly used in natural Japanese except in specific compound terms like クイックレスポンス (quick response) or product names. Avoid using it as a general translation for 'quick'.
猫の動きは素早い。
A cat's movements are quick.
迅速な対応をお願いします。
Please take quick action.
彼の回復は早かった。
His recovery was quick (happened early/soon).
Means 'quick and easy', often with a nuance of taking a shortcut. Casual.
手っ取り早く済ませよう。
Let's get it done quickly.
さっさと片付けて。
Clean it up quickly.
I've become quick-tempered lately.