When you use the present perfect tense, you bring to the present the action or state expressed by the verb. Even when an action may have started in the past, the present perfect tense is actually about the present.
For example, an action may have occurred in the past, but the effect of the action is still currrent as in the following sentence using the present perfect tense:
1. A continuing situation or state that started in the past
As you saw earlier, an action or state may have started in the past, but it is still ongoing in the present.
Common expressions: You often see this use of the present perfect tense with for or since:
- for + amount of time
- since + the starting point in time (in the past)
- I have worked at this company for 20 years.
(I started working there 20 years ago, and I still work there.)
- Antibiotics have existed for over 100 years.
(Antibiotics were discovered over 100 years ago and are still around today.)
- John has lived in Chicago all his life.
(John was living in Chicago when he was born, and he still lives there.)
- Senator Ecks has been a senator for a long time.
(Senator Ecks started being a senator a long time ago and is still a senator today.)
2. An experience, accomplishment, or change that is still important in the present
You use the present perfect tense to talk about experiences or accomplishments. The action or state may have happened in the past, but its effect carries on to the present.
Similary, you use the present perfect tense to express that something happened in the past that created a change that is still relevant in the present.
Note that in these situations, when the experience, accomplishment, or change happened is not important.
Common expressions: You often see this use of the present perfect tense with recently, before, never, and not yet.
Examples expressing prior experience
- Have you ever been to Japan?
(The focus is on the experience at present it does not matter when it may have happened.)
- I have been to Japan twice before.
(In the present, I can say that I have had this experience twice before.)
- I have already read this book.
(It doesn't matter when it happened, only that this book is on my list of books I have read.)
Examples expressing present accomplishment
- Mary has earned a degree in psychology and a degree in sociology.
(These are the degrees Mary has now; it does not matter when the earned them.)
- Oncologists have found a promising new treatment for cancer.
(It doesn't matter when they found it, only that they have a new treatment today.)
- The long-time senator has recently lost his re-election.
(It does not matter exactly when it happened, but he has lost.)
Examples expressing change with an effect in the present
- John has been promoted recently. He is a supervisor now.
(When he was promoted is unimportant, only the effect in the present.)
- My coffee has gotten cold.
(It does not matter when it go cold, only that my coffee is cold now.)
- Summers have been warmer lately due to climate change.
(The focus is on the present effect; there is no exact time in the past whent he change may have occurred.)
3. An action or thought ever or never experienced at any time before
Obviously, if an action or thought has never occurred, it has no link to the past; therefore, you should use the present perfect these.
Common expressions: You often see this use of the present perfect tense with ever, ever... before, never, and not... ever.
- Have you ever seen a ghost?
- Scientists have never observed black matter directly.
- I have never understood why people vote against their own interests.