at once

Meanings

1. 1phrasefixed phrase

   Immediately; without delay.

   Grammar: Often used in commands or urgent statements: Come here at once!

   Patterns

   • do something at once
   • come at once
   • leave at once

   The doctor told him to stop smoking at once.

   When she heard the news, she left the office at once.

   You must apologize at once.

2. 2phrasefixed phrase

   At the same time; simultaneously.

   Grammar: Used to say that two things happen together, often with 'all': all at once.

   Patterns

   • all at once
   • happen at once
   • speak at once

   The children all tried to speak at once.

   Don't do everything at once; take it step by step.

   The lights went out all at once.

Common combinations

all at once

The audience started clapping all at once.

come at once

If you see a fire, call the fire department and come at once.

stop at once

The teacher told the students to stop talking at once.

at once and for all

Let's settle this matter at once and for all.

Synonyms and how they differ

immediately

Immediately is more formal and common in writing; 'at once' is often used in spoken commands.

right away

Right away is informal and common in American English; 'at once' can sound a little more urgent or formal.

simultaneously

Simultaneously is formal and technical; 'at once' is the everyday way to say two things happen together.

Opposites

Commonly confused: at once or at all?

Practice

Make it your own

Write a sentence using “at once”, then check it and compare it with the examples above.

Explore more words