once
The word “once” indicates something happened one time and not more than that. This is also a subordinating conjunction for time.
- We have visited London only once. (one time)
- You need to get this finished at once. (at once = immediately)
- Once the house is built, they can move in. (once = right after; a little after)
once
a. once = one time
- I’ve only seen that movie once.
- You once said that you wanted to be a doctor. Is that still true?
- Valerie once worked as a stockbroker. Now she makes her living as an artist.
- We went to that coffee shop just once.
- Can’t they agree on anything–just once?
- They have used their bikes just once since getting them.
- People who are Muslim have the goal of visiting Mecca at least once during their lives.
- He was once a famous actor. Now very few people recognize him.
b. at once = immediately
Use “at once” when something is really urgent. It has to be done right now! You can also use “at once” for activities that are simultaneous (They happen at the same time.)
- He has to see his supervisor at once.
- I need you here at once.
- The runner realized at once that she had lost the race.
- Theresa was expecting an important call, so she checked her phone at once when it rang.
- The fact that he can work on all of these different projects at once is really amazing. (at once = at the same time)
- We can all communicate with each other at once on a Zoom call. (at once = at the same time)
- It’s hard to do two jobs at once. (at the same time)
- The government told the factory to shut down at once because the work environment was too dangerous.
c. once = a subordinating conjunction that means "after" or "when"
- Once the background check is finished, he can start his job.
- Tina and Mike got married once they both found good jobs.
- Once you realize the importance of good health, your eating habits change for the better.
- Let me know once she arrives so that I can talk to her.
- Once the rain lets up, we can go.
- The community felt enormous relief once the criminal was arrested.