Using
Before, After, While and When

We use these words (before,
after, while and when) to introduce time clauses to
tell when something happens.

Rudy washed the floor before
he watched the soccer match.
Rudy washed the floor after
the soccer match.
Rudy washed the floor when
the soccer match ended.
Rudy washed the floor while
he was watching the soccer match.

In all of these cases, Rudy washed the
floor. However, we have to look at the time clauses to see when
the floor was washed.

 

 

In all of these examples, the main
(independent) clause is "Rudy washed the floor". The time clause simply
states the relationship of other actions (watching the soccer match) to
the activity in the main clause.

Let's analyze the time sequence--with
another example.

 

The phone rang after we ate dinner.
(First we ate our meal, then
the phone rang.)

The phone rang before we ate dinner.

(First the phone rang, then we
ate.)

The phone rang when we ate dinner.

Also: The phone rang as we ate dinner.

(We ate and the phone rang at
the same time.)

The phone rang while we were eating
dinner.

Also: The phone rang as we were
eating dinner.

(This is the same as above, but
with the progressive tense [-ing]).

The Grammar

 

 

The phone rang is an independent
clause. It can stand alone.

before we ate dinner is a
dependent clause. It needs an independent clause to be a complete sentence.
It is a sentence fragment when it is used alone.

Punctuation

The phone rang before we ate dinner.

Before we could eat dinner, the
phone rang.

When the independent clause comes
first in the sentence, no comma is needed. When the dependent clause comes
first in the sentence, the clauses must be separated by a comma.

 

Different verb tenses

Look at these verb tenses:

It started to rain before I got home.

Jaime had a drink before he played
tennis.

(two past tense events)

I have to get home before it starts
of rain.

Jaime has to have a drink before
he plays tennis.

(modal auxiliary and present
tense)

Henry went to the movie after he
had dinner

Prof. Simon gave a test after the
spring break ended.

(two past tense events)

Henry may go to the movie after he
has dinner.

Prof. Simon ought to give a test
after the spring break ends.

(modal auxiliary and present
tense)

Myra was reading a book when the
phone rang.

(an on-going event interrupted
by a single event in the past)

Myra had to get up when the phone
rang.

(past tense cause and effect)

Ben asked for a ride when Myra answered
the phone.

(two past tense events)

Myra will leave to pick up Ben when
she hangs up.

(two future events)

I was listening carefully while the
manager was explaining the problem.

(two past tense continuous activities)

The doorbell rang while I was taking
a shower.

(one past tense continuous event
interrupted by single action)

Cause and Effect

You can use when or after
to explain some "cause and effect" situations.

Effect: He got a flat tire
(puncture).

Cause: He ran over some glass.

He got a flat tire after he ran
over some glass.

Cause: It rained.

Effect: Our paint job was
ruined.

When it rained, our paint job was
ruined.