Ingles

Present Perfect

The present perfect is used in the English language for narrate a fact that has already occurred, but does not have a specific time in the past, and may or may not be continuing inthe present.
The verb in the present perfect is accompanied with the auxiliary verb Have, and if the pronoun is in third person He, She, It is used Has, and immediately the participle of the verbpast simple, also known as the 3ª column.
Example

Affirmative
Noun + have/has + verb (past participle) + comp

- I have cut fruit
Yo he cortado fruta
- He has eaten pizza
El ha comido pizzaNegative
Noun + haven’t/hasn’t + verbo ( past participle ) + comp

- I haven’t studied for the test
Yo no he estudiado para mi examen
- She hasn’t seen TV
Ella no ha visto TV

QuestionHave/has + sujeto + verbo (pasado participio) + comp. + ?

- Have you been to your house?
¿Tú has ido a tu casa?
- Has he flown in airplane?
¿El ha volado en avión?

Forand Since

For and Since serve for delimit the time of the action of the verb.
For has the meaning of durante and since of desde.
Example

AffirmativeAffirmative
I have been here for sixteen years I have been here since 1994
He estado aquí durante 16 años He estado aquí desde1994

Negative Negative
I haven’t been here for two years I haven’t been here since 2009
No he estado aquidurante dos años No he estado aquí desde 2009

Just, already and yet

Just, already and yet set actions that have not yet finished.

Already: ya
Just: acabar de
Yet: todavíano, aun

Ya he hecho mis deberes
I have already done my homework
Acabo de hacer mis deberes
I have just dome my homework
Todavia no he hecho mis deberes
I haven’t done my homework yet...