The document discusses the present perfect tense and present perfect progressive tense in English. It provides examples of how each tense is used, including to express actions that happened before now at an unspecified time, repetitive actions before now, and situations that began in the past and continue to the present. It also compares the present perfect to the simple past and discusses when to use the present perfect progressive versus the present perfect.

1. The Present Perfect
Have/Has + Past Participle

2. Time ?
X X

3. 1.The present perfect expresses the
idea that something happened
before now, at an unspecified time in
the past
Time ?
X X

4. 1.The present perfect expresses the
idea that something happened
before now, at an unspecified time in
the past

5. 1.The present perfect expresses the
idea that something happened
before now, at an unspecified time in
the past
The Raelians claim that they have cloned
human beings.

6. 1.The present perfect expresses the
idea that something happened
before now, at an unspecified time in
the past
The Raelians claim that they have cloned
human beings.
Has anyone succeeded in cloning animals?

7. 1.The present perfect expresses the
idea that something happened
before now, at an unspecified time in
the past
The Raelians claim that they have cloned
human beings.
Has anyone succeeded in cloning animals?
The egg has had its nucleus removed.

9. The adverbs ever, never, already,yet
still, and just are frequently used
with the present perfect.

10. The adverbs ever, never, already,yet
still, and just are frequently used
with the present perfect.
Human beings haven’t been successfully
cloned yet.

11. The adverbs ever, never, already,yet
still, and just are frequently used
with the present perfect.
Human beings haven’t been successfully
cloned yet.
I have already seen that video on stem cell
research.

12. The adverbs ever, never, already,yet
still, and just are frequently used
with the present perfect.
Human beings haven’t been successfully
cloned yet.
I have already seen that video on stem cell
research.
Dr. Suzuki started writing a complaint letter
to the newspaper, but he still hasn’t finished
it.

13. The adverbs ever, never, already,yet
still, and just are frequently used
with the present perfect.
Human beings haven’t been successfully
cloned yet.
I have already seen that video on stem cell
research.
Dr. Suzuki started writing a complaint letter
to the newspaper, but he still hasn’t finished
it.
Alex feels bad. He has just heard some bad
news.

14. X X
X XX

15. 2. The present perfect also
expresses the repetition of an
activity before now.The exact time
of repetition is not important.
X X
X XX

16. 2. The present perfect also
expresses the repetition of an
activity before now.The exact time
of repetition is not important.

17. 2. The present perfect also
expresses the repetition of an
activity before now.The exact time
of repetition is not important.
We have had four tests so far this semester

18. 2. The present perfect also
expresses the repetition of an
activity before now.The exact time
of repetition is not important.
We have had four tests so far this semester
There have been many cloning experiments
done on mice.

19. 2. The present perfect also
expresses the repetition of an
activity before now.The exact time
of repetition is not important.
We have had four tests so far this semester
There have been many cloning experiments
done on mice.
Dr. Suzuki has spoken on the subject of
cloning many times.

20. 3.The present perfect also expresses
a situation that began in the past
and continues to the present.
These verbs are usually stative verbs.

21. 3.The present perfect also expresses
a situation that began in the past
and continues to the present.
These verbs are usually stative verbs.
I have been here since seven o’clock.

22. 3.The present perfect also expresses
a situation that began in the past
and continues to the present.
These verbs are usually stative verbs.
I have been here since seven o’clock.
We have been here for two weeks.

23. 3.The present perfect also expresses
a situation that began in the past
and continues to the present.
These verbs are usually stative verbs.
I have been here since seven o’clock.
We have been here for two weeks.
Scientists have known this fact for a very
long time.

24. 3.The present perfect also expresses
a situation that began in the past
and continues to the present.
These verbs are usually stative verbs.
I have been here since seven o’clock.
We have been here for two weeks.
Scientists have known this fact for a very
long time.
I have liked watching science documentaries
ever since I was a child.

25. Difference between
since and for
Since + a particular time (1984, 2 pm, etc.)
For + a duration of time (2 weeks, half an
hour, etc.)

26. Present perfect
vs.simple past

27. Present perfect
vs.simple past
1. Most countries (ban) ______________
by law human reproductive cloning.

28. Present perfect
vs.simple past
have banned
1. Most countries (ban) ______________
by law human reproductive cloning.

29. Present perfect vs.
simple past

30. Present perfect vs.
simple past
2. Dolly the sheep (be, not)
___________ the first animal to be
cloned.

31. Present perfect vs.
simple past
2. Dolly the sheep (be, not)
was not
___________ the first animal to be
cloned.

32. Present perfect
vs.simple past

33. Present perfect
vs.simple past
3. Japanese studies (show)
______________ that cloned mice live in
poor health.

34. Present perfect
vs.simple past
3. Japanese studies (show)
have shown
______________ that cloned mice live in
poor health.

35. The Present Perfect
Progressive
1. This tense is used to indicate the duration
of an activity that began in the past and
continues to the present. When the tense
has this meaning, it is used with time words
such as, for, since, all morning, all day, all
week.

36. The present perfect
progressive

37. The present perfect
progressive
For years, scientists have been working on
ways to successfully clone animals.
Al Gore has been studying climate change
for twenty straight years.
Scientists have been debating the issue of
human reproductive cloning for years.

38. The present perfect
progressive
2. When the tense is used without any
specific mention of time, it expresses a
general activity in progress recently, lately.

39. The present perfect
progressive
He has been thinking about doing something
to save our environment.
All of the students have been studying hard
for the final.
My back hurts, so I have been sleeping on
the floor lately. The bed is too soft.

40. The present perfect
progressive
3. With certain verbs (most notably live,
work, teach), there is little or no difference
in meaning between the two tenses when
since or for is used.

41. present perfect
progressive
I have lived here since 1995. = I have been
living here since 1995.
He has worked at the same institution for
ten years. = He has been working at the
same institution for ten years.

42. Present perfect /
progressive?
Scientists (warn)____________that it
would be unethical to contemplate
adapting the method to help infertile
couples have their own biological
children.

43. present perfect or
progressive?
Scientists have warned that it would be
unethical to contemplate adapting the
method to help infertile couples have
their own biological children.

44. present perfect or
progressive?
Scientists (conduct) ____________
experiments for years in an attempt to
create a complex organism that is a
clone of another organism.

45. present perfect or
progressive?
Scientists have been conducting
experiments for years in an attempt to
create a complex organism that is a
clone of another organism.

46. present perfect or
progressive?
Scientists (clone) ________ animals for
many years.

47. Scientists have been cloning animals for
many years.