GRAMMAR
Present Perfect

It has been ….

It has been + time + since + sentence

  • ​Must learn grammar.​
  • ​It's = It has
  • Event in the Past + Present and Continuing = Present Perfect

EXAMPLES

  • Makes 50 years since the first man set foot on the Moon. <- INCORRECT
  • It has been 50 years since the first man set foot on the Moon.  <- CORRECT
You've studied English grammar, right?
Yes, but it has been a long time since I studied English grammar.
How long has it been since you have been to Europe?
It's been a couple of years at least.
How long since you were last working at Google?
It's been over  a year now.
How long have you been wearing braces?
It's been 6 months since I started using braces.