0

How could I use has/have with passive.

For example,

This has already proofed in 1990.

or

This has already been proofed in 1990.

Which one is correct?

2
  • "This has already been proven." or "This was already proven in 1990". We don't use specific time phrases like "in 1990" with Present Perfect. Jan 8 '19 at 10:09
  • @CowperKettle Thanks a lot. Could you please post it as an answer, this will be very helpful.
    – Maryam
    Jan 8 '19 at 10:18
2

"This has already been proven." or "This was already proven in 1990". We don't use specific time phrases like "in 1990" with Present Perfect.

1

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .