Translation guide
The English phrase "one-by-one" describes doing things individually, in sequence, or dealing with items separately. In Japanese, this concept is expressed through various adverbs, phrases, and grammatical patterns depending on whether you emphasize order, individuality, or thoroughness.
To do or handle things one at a time, in order, without skipping or grouping.
The most common and versatile way to say 'one by one' for countable items. It emphasizes doing things individually and in order.
問題を一つずつ解決していきましょう。
Let's solve the problems one by one.
He took the apples out of the box one by one.
Specifically for people: 'one person at a time' or 'each person individually'.
生徒たちは一人ずつ部屋に入った。
The students entered the room one by one.
Means 'in turn' or 'in order'. It focuses on the sequence rather than the individuality, but often overlaps with 'one by one'.
順番に名前を呼ばれた。
Our names were called one by one.
Used for small, often round or generic objects. More specific counter than 一つ, but similar in meaning.
飴を一個ずつ配った。
I handed out the candies one by one.
To emphasize dealing with things singly, not all at once, often to avoid confusion or to focus.
Similar to 一つずつ but can imply careful attention to each item. Often used when explaining or checking things meticulously.
手順を一つ一つ確認してください。
Please check the steps one by one.
Means 'separately' or 'individually'. It highlights that things are not done together, but doesn't necessarily imply a sequence.
これらの問題は別々に扱うべきだ。
These issues should be dealt with one by one.
To express doing something in stages or little by little, often with a sense of progression.
Means 'little by little' or 'bit by bit'. It's used for gradual processes, not necessarily discrete items, but can translate 'one by one' in contexts of gradual accumulation.
少しずつ慣れていきます。
I'll get used to it one step at a time.
Literally 'one step at a time'. Used metaphorically for progress in learning, projects, etc.
一歩ずつ前に進もう。
Let's move forward one step at a time.
Both mean 'one by one', but 一つずつ (hitotsu zutsu) emphasizes distribution or sequential action, while 一つ一つ (hitotsu hitotsu) often implies careful, individual attention. 一つずつ is more common in everyday instructions; 一つ一つ is used when stressing thoroughness.
書類を一つずつファイルに入れた。
I put the documents into the file one by one.
書類を一つ一つ確認した。
I checked the documents one by one (carefully).
The pattern [counter] + ずつ is very productive. Replace 一つ with the appropriate counter: 一人ずつ (one person at a time), 一枚ずつ (one flat object at a time), 一匹ずつ (one small animal at a time), etc. This is the most natural way to express 'one by one' for specific noun classes.
先生は生徒を一人ずつ呼んだ。
The teacher called the students one by one.
彼女は貝殻を一つずつ拾った。
She picked up the shells one by one.