2.1.1. Complete list of present perfect forms.

USE 1: Unespecified time before now

  • We use the present perfect to say that an action happened at an unspecified 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.

Haga clic aquí para ver el ejemplo.

  • I have seen that movie twenty times.
  • I think I have met him once before.
  • There have been many earthquakes in California.
  • People have traveled to the Moon.
  • People have not traveled to Mars.
  • Have you read the book yet?
  • Nobody has ever climbed that mountain.
  • A: Has there ever been a war in the United States?
  • B: Yes, there has been a war in the United States.