Translation guide
The English phrase "at once" has two main meanings: "immediately" and "simultaneously." This guide helps learners choose the right Japanese expression for each meaning, with natural examples and usage notes.
Expressing that something happens without delay, right now, or instantly.
The most common and versatile word for "immediately" or "right away." Used in casual and formal contexts.
すぐ行きます。
I'll go at once.
It will finish at once.
Formal and often used in official announcements, instructions, or written contexts. Stronger sense of urgency than すぐ.
Evacuate at once.
Means "instantly" or "on the spot." Often used for reactions or decisions made without hesitation.
He answered at once.
Implies doing something promptly, often with a sense of eagerness. Common in phrases like 早速ですが ("without further ado").
Let's begin at once.
Expressing that two or more things happen at the same time.
The standard way to say "at the same time" or "simultaneously." Works in most contexts.
They both started talking at once.
Often used when multiple actions or items are handled in one go, or when something happens all at once. Slightly more colloquial than 同時に.
Used when a group does something all together at the same moment, like a coordinated action.
すぐ is the everyday word for "immediately." 直ちに is formal and urgent, often used in commands or warnings. 即座に emphasizes an instant reaction, common in narratives.
Come at once. (casual)
Come at once. (stern command)
He stood up instantly.
English "at once" can mean either "immediately" or "simultaneously." In Japanese, these are expressed with different words. Using すぐ for "simultaneously" or 同時に for "immediately" will cause confusion.
I can't do two things at once.
一度に全部食べないで。
Don't eat everything at once.
Many people came at once.
The students stood up at once.