Bill Gates has been very successful in business as the CEO of Microsoft Corporation since 1975. He has programmed computers since his early teens and has always loved working with computers. For the last three decades, millions of people have used his computer programs and Gates has written several books during that time. He and his wife Melinda have also donated billions of dollars to schools and organizations working in global health since the 1990s.

1. Present Perfect:
Since and For
Bill Gates and
Microsoft
6
Focus on Grammar 3
Part IV, Unit 16
By Ruth Luman, Gabriele Steiner, and BJ Wells
Copyright © 2006. Pearson Education, Inc. All rights reserved.

2. Who Is Bill Gates?Who Is Bill Gates?
Bill Gates is one of the richest and most
successful business executives in the world.
Millions of people have used his computer
programs for the past three decades.
Bill Gates has always loved working with
computers. In fact, he has programmed
computers since his early teens.
He has been the CEO of Microsoft Corporation
since 1975. Since then, Bill Gates has written
several books and has given billions of dollars to
schools. For the last several years, he and his
wife Melinda have donated a substanial amount
of money to organizations working in global
health.

3. Form 1Form 1
The present perfect is formed with:
Bill Gates has beenhas been the CEO since 1975.
Many people have usedhave used Microsoft’s programs.
+form of
have
past
participle

4. Form 2Form 2
Past participles can be regularregular or irregularirregular.
Gates has always lovedloved
working with computers.
The regular form of the past participle is
base form of verb + -d or -ed.
The regular form of the past participle is
base form of verb + -d or -ed.

5. Gates has beenhas been the CEO since 1975.
He and his wife have givenhave given lots of money to schools.
Form 3Form 3
There are many
irregular past participles.
There are many
irregular past participles.
Past participles can be regular or irregular.

6. Form 4Form 4
Note these common irregular past participlescommon irregular past participles.
write – written
give
– given
be – been
see – seen
read –
read do

7. Bill Gates has been CEO of Microsoft since 1975.
Present PerfectPresent Perfect
Use the present perfect to talk about something that
began in the past and continues into the present (and
may continue into the future).
future
1975
past
now
since 1975.
has been CEO

8. Bill Gates has written several books since 1975.
Using Since 1Using Since 1
Use the present perfect with since + point in time
to show when something started.
future
1975
past
now
since 1975.
has written several books

9. Gates has programmed computers since he was 13 years old.
Using Since 2Using Since 2
SinceSince can also introduce a time clause.
future
age 13
past
now
since he was 13 years old.
has programmed computers
time clausetime clause

10. Change the sentences to present
perfect. Add the since phrase in
parentheses and delete any past
tense time phrases.
Maria was in the garden yesterday. (since 9 a.m.)since 9 a.m.)
Practice 1Practice 1
Maria has been in the garden since 9 a.m.Maria has been in the garden since 9 a.m.
1. Bill Gates wrote many emails yesterday. (since 1975)since 1975)
2. They gave a lot of books to schools last year. (since 1990)since 1990)
3. I saw many friends last weekend. (since I came home)since I came home)
4. My sister read many articles last night. (since last August)since last August)
5. My friend worked at a pizza place a year ago. (since 2003)since 2003)
Example:
Bill Gates has written many emails since 1975.Bill Gates has written many emails since 1975.
They have given a lot of books to schools since 1990.They have given a lot of books to schools since 1990.
I have seen many friends since I came home.I have seen many friends since I came home.
My sister has read many articles since last August.My sister has read many articles since last August.
My friend has worked at a pizza place since 2003.My friend has worked at a pizza place since 2003.

11. Millions of people have used Gates’s
software for the last three decades.
Using ForUsing For
Use for + length of time to show how long
something has lasted.
futurepast
now
for the last three decades.
have used Gates’s software
for three decades

12. Since and ForSince and For
Note the difference between sincesince and forfor .
five o’clock
yesterday
last summer
1996
he was a child
since + point in
time
for + length of
time
ten minutes
two days
three decades
many years
a long time

13. Complete the sentences with
since or for.
Bill Gates has been married to Melinda
French Gates ___________ 1994.
Practice 2Practice 2
1. Computers have been used in schools __________ more
than a decade.
2. I have had a computer in my office __________ the mid-
1990s.
3. Many students have worked with computers __________
many years.
4. My computer hasn’t given me any problems __________
last year.
Example:
sincesince
forfor
sincesince
forfor
sincesince

14. ReferencesReferences
Copyright © 2006 Pearson Education and
its licensors. All rights reserved.