Translation guide
The English word 'alternate' has two main uses: as a verb meaning to switch back and forth between two things, and as an adjective meaning every other one or a substitute. This guide covers natural Japanese expressions for each meaning.
Expressing that two things, actions, or states occur in turn, repeatedly.
This is the most common and natural way to say 'alternate A and B'. 交互に means 'alternately' or 'in turn'. Replace V with an appropriate verb.
He alternated his left and right feet.
Sunny and rainy weather alternated.
An adverb meaning 'by turns' or 'alternately', often used when people take turns doing something. Slightly more casual than 交互に.
We alternated driving.
Used when people alternate in a role or task, like taking shifts. Implies a scheduled or organized rotation.
They alternate night shifts.
Describing a pattern where something happens or appears on every second item in a series.
Means 'every other one' or 'at intervals of one'. Can be used with days, objects, etc. The counter changes depending on what is being counted (e.g., 一日おきに for days).
He sat in every other seat.
Take this medicine every other day.
Used as an adjective meaning 'alternate' or 'alternating', often for patterns like stripes or layers.
alternating red and white stripes
Referring to a person or thing that can be used instead of another, especially in a plan or role.
The most common way to say 'alternate' in the sense of a substitute person or thing. 代わり means 'substitute' or 'replacement'.
He played in the match as an alternate.
Please think of an alternate plan.
A more formal term for 'alternative' or 'substitute', often used in technical or business contexts.
We need to find alternate energy sources.
Specifically refers to a reserve or backup person, like an understudy or a substitute player waiting on the bench.
The alternate players are warming up.
Both mean 'alternately', but 交互に is more common for inanimate things or abstract patterns (e.g., weather, colors), while 代わる代わる is used specifically for people taking turns doing an action. 交互に can also be used for people, but 代わる代わる emphasizes the voluntary turn-taking aspect.
There is no single Japanese verb that directly translates 'to alternate'. Instead, use adverbial phrases like 交互に or 代わる代わる with a verb. Saying 「オルタネートする」 is not natural Japanese.