English Tenses
Present Perfect Tense
There are two present perfect tenses in the English language.
Present perfect simple Form Positive statement:
I have cooked,
I have written ,
He has cooked,
He has written (I've cooked, He's cooked)
Negative statement: I have not worked (I haven't worked), He has not worked (He
hasn't worked)
Question: Have you worked?
Neg. question: Have you not worked? (Haven't you worked?)
Use The present perfect combines the past and present.
1. We use the present perfect simple for actions or states that started in the past
and still continue.
1- We have lived here since 2001.
2- She has known me for more than two years.
3- I haven't seen her since Christmas.
4- How long have they been here?
It is often used with expressions indicating that the activity began in the past
and comes up to now, such as:
for 10 years, since 1995, all week, all the time, always, lately, recently ... We
have always worked in York. (We still work in York.)
It has been quite cold lately. (It is still cold.)
If the activity started in the past and ended in the past we cannot use the present
perfect.
I have smoked for 5 years. (present perfect - I still smoke.) I smoked for 5
years. (past simple - I smoked from 2000 to 2005, then I stopped.)
2. We use it to describe an experience that happened in the past (the time is
not given), but the effects are important now.
She has been to London. (And so she knows London.)
Compare:
I have already been to Greece. (experience - And I want to go somewhere else
now.)
I have been in Greece for two weeks. (state - I am stlill in Greece.)
When we use this tense to express some experience, we can use following
adverbs - ever, never, already, often, occassionaly, yet, before ......
Have you ever tried it?
She has never read this book.
We haven't seen it yet.
Have you fallen off a bike yet?
I haven't met her before.
3. The present perfect simple is used for past activities that have a present
result.
The bus hasn't arrived. (It did not arrived on time and we are still waiting now.)
I have bought a new house. (I did it last month and it means that now I have a
new address.) For such activities we often use these adverbs - yet, already, just.