We use the Present Perfect Simple to say that an action happened at an un specific time before now.The exact time is not important. You cannot use the Present Perfect with specific time expressions such as: yesterday, one year ago, last week, when I was a child, when I lived in Japan, at that moment, that day, one day, etc. We can use the Present Perfect with unspecific expressions such as: ever, never, once, many times, several times, before, so far, already yet, etc.
We only use the verb to have (haber). We use have or has in present:Subject + have/has + Past participle + ComplementPositive = I have eaten a pizzaNegative = I haven't (or have not) eaten a pizzaInterrogative = Have I/you eaten a pizza?
FOR AND SINCE:For and Since are time expressionsWe write them at the end of the sentenceSubject + have/has + Past Participle + Complement = since/for + .....For (durante): Periods of time. Example: for five yearsSince (desde): oints in the time. Example: since 1987
Formation:Positive: Subject + verb in infinitive + complementNegative: Subject + don't/doesn't + verb in infinitive + complementInterrogative: Auxiliar verb (do/does) + Subject + verb infinitive + complement.
Present Perfect Simple