As (Reason and Time)
Using as to mean 'at the same time as' or 'because', and choosing between as and when
As = At the Same Time As
Use as when two things happen together at the same time.
- We all waved goodbye to Liz as she drove away. (we waved and she drove away at the same time)
- *As I walked along the street, I looked in the shop windows.*
- Can you turn off the light as you go out, please?
You can also say that something happened as you were doing something else (in the middle of doing something else):
- Kate slipped as she was getting off the bus.
- We met Paul as we were leaving the hotel.
Just As
Use just as to mean “exactly at that moment”:
- *Just as I sat down, the doorbell rang.*
- I had to leave just as the conversation was getting interesting.
Two Things Changing Together Over Time
As can also describe two things changing together over a longer period:
- *As the day went on, the weather got worse.*
- I began to enjoy the job more as I got used to it.
As = Because
As also means “because”:
- *As I was hungry, I decided to find somewhere to eat.* (= because I was hungry)
- *As it’s late and we’re tired, let’s get a taxi home.* (= because it’s late)
- We watched TV all evening as we didn’t have anything better to do.
You can also use since in this way:
- *Since it’s late and we’re tired, let’s get a taxi home.*
As vs. When
This is an important distinction. Use as only when two things happen at the same time. Use when (not as) when one thing happens after another.
| As (at the same time) | When (one thing after another) |
|---|---|
| *As I drove home, I listened to music.* | *When I got home, I had something to eat.* (not |
Be careful: as can also be confused with when in “because” sentences.
| As (= because) | When (= at the time) |
|---|---|
| David wasn’t in the office as he was on holiday. (= because he was on holiday) | David lost his passport when he was on holiday. (= during the time he was away) |
| *As they lived near us, we used to see them quite often.* (= because they lived near us) | *When they lived near us, we used to see them quite often.* (= at the time they lived near us) |
Common Mistakes with As and When
Use when (not as) to talk about an age or a point in time in someone’s life:
- Julia got married when she was 22. (not
as she was 22) - I used to live near the sea when I was a child. (not
as I was a child)
Quick Self-Check
I burnt myself _____ I was taking a hot dish out of the oven.
Select your answer:
_____ we don't use the car very often, we've decided to sell it.
Select your answer:
_____ I got to the airport, I checked in immediately.
Select your answer:
The train slowed down _____ it approached the station.
Select your answer:
I used to live near the sea _____ I was a child.
Select your answer: