"Once" and "as soon as" are conjunctions that join two sentences.

They are used to show that one event or action happens immediately after another event or action.

"Once" and "as soon as" have the same basic meaning as "after", but they emphasize the 2nd action or event starts immediately after the 1st action or event finishes.

We can say that "once" and "as soon as" have the same meaning as "immediately after".

• I fell asleep immediately after I got in my bed.
• I fell asleep as soon as I got in my bed.
• I fell asleep once I got in my bed.

Here is how we make these sentences.

Action/Event 2 + as soon as/once + action/event 1

• She poured herself a glass of wine as soon as she came into the house.
• The bag broke as soon as I left the store.
• She will come once she has finished her work.
• They called us once they heard the news.
• I will tell you as soon as I find out.
• Please email me as soon as you find out what is going on.

We can also switch the order of the sentence.

As soon as/Once + action/event 1, + action/event 2

If "as soon as" or "once" is at the beginning of a sentence, then separate the two parts with a comma when writing.

• As soon as she heard the news, she started crying.
• Once she arrived, we started eating.
• Once he started his speech, everyone started cheering.
• As soon as it started to rain, we went inside.
• Once I sat down, I felt better.
• As soon as I ate something, I felt sick.

Practice speaking English and improve your English grammar by finishing the sentences below and then practice making your own sentences. It is a great way to learn English and improve your English fluency!

I _______________ as soon as I finished work.
I _______________ once I finished work.
I _______________ as soon as I got home.
I _______________ once I got home.
My family _______________ as soon as I told them _______________.
My friends _______________ once they heard that _______________.
Once it started to rain, we _______________.
As soon as I saw her, I _______________.
Once the CEO walked in, everybody _______________.
As soon as it happened, we all _______________.
I _______________ as soon as _______________.
I _______________ once _______________.
She will _______________ as soon as she finds out.
They will _______________ once they hear about _______________.