Translation guide
The English word 'doubling' can refer to making something twice as much, folding something in two, or having a dual purpose. This guide covers natural Japanese expressions for these core meanings.
We doubled the production volume.
Please double my salary.
A more formal or written term meaning 'to double' or 'to increase twofold'. Often used in news or business contexts.
Profits doubled.
Intransitive version meaning 'to become double'. Use when the subject itself doubles.
The population doubled.
To bend or fold something so that one part covers the other, often making it half the size.
General verb for folding something like paper, cloth, or a thin object. Often used with '二つに' (in two).
Please fold the paper in half.
Specifically means to fold something up compactly, like a map, chair, or clothes. Implies a neat, compact fold.
Literally 'to make into a two-fold'. Used for folding something exactly in half, like a letter or a sheet.
I folded the letter in half.
When something serves two roles or is used for two different things at the same time.
Pattern meaning 'to serve also as' or 'to double as'. Attach to a noun. Very common for dual-purpose items or roles.
This room doubles as a study.
He doubles as manager and player.
Idiomatic phrase meaning 'to play two roles' or 'to double up on duties'. Often used for people taking on multiple responsibilities.
To turn around and go back in the direction one came from, often suddenly.
倍にする is the everyday expression for 'to double' something. 倍増する is more formal and often used in economic or statistical contexts. For casual speech, stick with 倍にする.
English often uses the gerund 'doubling' as a noun (e.g., 'the doubling of prices'). In Japanese, it's more natural to rephrase using verbs like 倍になる or 倍にする, or use noun phrases like 倍増.
The doubling of the population caused housing problems.
He doubled his investment in just one year.
I folded up the map.
She doubles as a secretary and accountant.