Present perfect simplethe present perfect simple its formed by the present simple of the verb to have + the past participle of the principal verb. Remember: the past participle of the regular verbs its like the past.
Afirmative:I/you 've watched tv (have)
He/she/it 's watched tv (has)
we/you/they 've watched tv (have)
Negative:I/you haven't wathed tv (have not)
He/she/it hasn't watched tv (has not)
we/you/they haven't watched tv (have not)
Interrogative:Have I watched tv?
Has you/he/she/it watched tv?
Have we/you/they watched tv?
Short answer:Yes, I have/No, " haven't
Yes, you have/No, " haven't
Yes, he/she/it has/No, " hasn't
Yes, we/you/they have/No, " haven't
Use:To talk about actions in the past that are important in the present:
Actions ocurred in the past without explanation of the moment.
ex:I have met your mother in the supermarket
The adverb just express recently actions:
ex:We have just come back from London
With the prepositions for and since
ex:She has been abroad sonce 1999
I haven't eat pizza for two weeks
With expresions of time taht indicate a incomplete period: today, this morning, this week, this month, this year...
ex:I haven't done much today
Present perfect continuousIts formed with the present perfect of the verb to be + the principal verb finished in -ing
Afirmative:I/you have been jumping
He/she/it has been jumping
We/you/they have been jumping
Negative:I/ you haven't been jumping
He/she/it hasn't been jumping
We/you/they haven't been jumping
Interrogative:Have I/you been jumping?
Has he/she/it been jumping?
Have we/you/they been jumping?
Use:We use the present perfect continuous to:
To talk about an activity started in the past and continues in the present. Normally it uses the prepositions: for and since.
ex:We have beenn cooking since 9 o'clock
To talk about a started action recently finished.
ex:You have been sleeping all morning.
To talk about past actions recently finished with evident results.
ex:Have you been hunting frogs?