Time clauses and Conjunctions
We can join two sentences using a conjunction. A conjunction is a 'linking' word or phrase. A time conjunction gives us information about when two events happen, relative to each other.
Common time conjunctions are:
As soon as
When can be used to show that one event is before, or at the same time as another event. When can be used to illustrate a past or future meaning.
I studied abroad for a year when I was at university.
When she finishes this course, she'll go abroad for a year.
As soon as means that the second event happened, or will happen, immediately after the first.
In the second example below, the verb in the present simple has a future meaning.
As soon as I finished lunch, I went out for a walk.
I'll go out for a walk as soon as I finish lunch.
Not … until means the same as not … before.
I didn't leave home until I got married.
I didn't learn to drive a car until I was 21.
After and before can be followed by a subject-verb clause or by a gerund.
After I had eaten five ice cream cones, I felt a little sick.
Before coming back to Britain, I travelled all over Eastern Europe.
While can be used to show two events happening at the same time.
While you're getting lunch ready, I'll wash the car.
I studied judo while I was in Japan.
While and During
While and during are both used to show that two things happen at the same time.
While is a conjunction and is used before a subject-verb clause.
During is a preposition and is used before a noun phrase.
What should you do during an earthquake?
Don't run downstairs while the building is shaking.
He arrived while I was eating breakfast.
He arrived during breakfast.