As can mean at the same time as, for two things happening together (use when if one follows the other), and as can mean because.
A as = at the same time as
Use as when two things happen at the same time. You can also say something happened as you were in the middle of doing something else (past continuous: see Unit 6).
Just as means at exactly that moment. As also links two things that change together over a longer period.
Use when, not as, if one thing happens after another.
- The children waved to their gran as the train pulled out.
- As I walked down the high street, I looked in the shop windows.
- Could you switch the light off as you go out?
- Kate slipped as she was getting off the bus.
- We ran into our old teacher as we were coming out of the cinema.
- Just as I sat down, the phone rang.
- My phone died just as the film was reaching the best part.
- As the evening wore on, the room got colder.
- The language got easier as I picked up more words.
- As I cooked, I listened to a podcast. (at the same time)
- When I arrived at work, I made a coffee. (not As I arrived)
B as = because
As also means because. Since works the same way.
Compare: as (because) and when (at the time).
- As I was starving, I made myself a sandwich.
- As the shops are shut and it's raining, let's stay in.
- Since the shops are shut and it's raining, let's stay in.
- We watched telly all evening as there was nothing better to do.
- As I never use my bike these days, I gave it to my niece.
- Dev wasn't at work as he was on holiday. (because)
- Dev lost his passport when he was on holiday. (during that time)
- As they lived near us, we saw them quite often. (because)
- When they lived near us, we saw them quite often. (at that time)
Exercises
116.1 Here as means at the same time as. Join each sentence with the right ending, using as. Endings: we were cycling down the hill; I was lifting the pan off the hob; the train pulled out; he read the letter aloud; the band walked on stage.
The children waved to their gran ...
The children waved to their gran as the train pulled out.
The children waved to their gran as the train pulled out.
We all sat in silence ...
We all sat in silence as he read the letter aloud.
I scalded my hand ...
I scalded my hand as I was lifting the pan off the hob.
The audience screamed ...
The audience screamed as the band walked on stage.
A deer leapt across the lane ...
A deer leapt across the lane as we were cycling down the hill.
116.2 Here as means because. Join the halves, beginning with As. Second halves: we had a picnic in the park; I took my shoes off at the door; I made myself a sandwich; the post office is closed; you can borrow my bike.
I was starving
As I was starving, I made myself a sandwich.
As I was starving, I made myself a sandwich.
it's Easter Monday
As it's Easter Monday, the post office is closed.
the carpet was brand new
As the carpet was brand new, I took my shoes off at the door.
I'm not using it this week
As I'm not using it this week, you can borrow my bike.
the sun was out
As the sun was out, we had a picnic in the park.
116.3 What does as mean in each sentence: because, or at the same time as?
As she worked nights, we hardly ever saw her.
because
As she worked nights, we hardly ever saw her.
Kate slipped as she was getting off the bus.
Kate slipped as she was getting off the bus.
As I was shattered, I went to bed early.
As I was shattered, I went to bed early.
Unfortunately, as I was parking, I hit the car behind me.
Unfortunately, as I was parking, I hit the car behind me.
As we walked along the cliff path, the wind got stronger and stronger.
As we walked along the cliff path, the wind got stronger and stronger.
We decided to eat out as there was no food in the house.
We decided to eat out as there was no food in the house.
As we hardly ever use the car, we've decided to sell it.
As we hardly ever use the car, we've decided to sell it.
116.4 In some of these sentences as is wrong. Write OK, or write the correct sentence.
Julia got married as she was 22.
Julia got married when she was 22.
Julia got married when she was 22.
As the evening wore on, the room got colder.
OK
As the evening wore on, the room got colder.
She tripped as she was carrying the tray upstairs.
She tripped as she was carrying the tray upstairs.
I met my wife as I was at university.
I met my wife when I was at university.
As I finished my degree, I had no idea what job I wanted.
When I finished my degree, I had no idea what job I wanted.
The plane shook as it came in to land.
The plane shook as it came in to land.
We spent every summer in Wales as I was young.
We spent every summer in Wales when I was young.
We can cycle to the lake as it's only a couple of miles.
We can cycle to the lake as it's only a couple of miles.
116.5 Complete these sentences with your own ideas.
Just as I got into the bath, ...
Example answer: Just as I got into the bath, the phone rang.
I saw you as ...
Example answer: I saw you as I was getting off the bus.
It started to rain just as ...
Example answer: It started to rain just as we set off.
As she doesn't have a phone, ...
Example answer: As she doesn't have a phone, I'll have to write to her.
Just as I took the picture, ...
Example answer: Just as I took the picture, somebody walked in front of me.