ONE THING BEFORE ANOTHER

before  /  before that  /  previously  /  earlier  /  formerly

Before I went to work, I fed the cat.
Before going to work, I ran a mile.  ► formal / written style

It was nice to be in Mexico City.
Previously I'd been to Cancun and Guadalajara.  ► fairly formal
Before that, I'd been to Cancun and Guadalajara.  ► less formal
 
I was in the office by 2:30.
Earlier I was out.  ► fairly formal
Before that, I was out.  ► less formal

The Dodgers are a Los Angeles baseball team. Formerly they were the Brooklyn Dodgers,  ► at an earlier time

THINGS HAPPENING AT THE SAME TIME

while  /  as  /  during  /  throughout

While I waited, I read the newspaper.  ► fairly formal
While waiting, I read the newspaper.  ► more formal
(the waiting and reading happened together)

As I was driving to work, I saw an accident.
(As is about the same as while.)

I saw her just as she was turning the corner.
(simultaneously; at that precise moment)

During the war, I lived in Canada.
(does not specify how long)

Throughout the war, food was rationed.
(from beginning to end)

Whenever I see a sentimental movie, I can't help crying.  ► every time

ONE THING AFTER ANOTHER

after  /  after that  /  afterwards  /  first  /  following

After I locked up, I went to bed.  ► fairly formal
After locking up, I went o bed.  ► more formal

First we went to the movies. After that, we went out for coffee.
He was rushed to the hospital. He died soon afterwards.
(In these two examples, after that and afterwards are interchangeable.)

Following my visit to Paris, I bought two books about it.  ► fairly formal

TIME WHEN

when  /  as soon as  /  once  /  the moment  /  the minute

When I'm rich, I'll buy a yacht.
'When I will be rich'   ►  not correct

As soon as we finish packing, we can leave.  ► immediately after
Once we finish packing, we can go out.  ► after, but less specific

The moment I saw Monica's face, I fell in love with her.
The minute I saw Paulo, I knew I'd met him before.

CONNECTING TWO PERIODS OR EVENTS

in the meantime  /  until then  /  till then  /  by the time

Dinner will take about an hour. In the meantime, relax and have a drink.  ► between now and dinner

The new computers are arriving soon. Till then, we'll just use the old ones.  ► informal for Until then

By the time I retire, I will have worked here for 26 years.
'... I will work here for 26 years"   ►  not correct

On the next pages you will be able to practise this grammar.