I want to know that: does the perfect tense function it proper usage when it preceded by “to” infinitive.
I was taught that we couldn’t put “ago” with present perfect.
So, I came across a sentence such as the following:
- These lions seem to have existed 70 years ago
Isn’t the same as?:
- These lions have existed 70 years ago. incorrect
Warning: Cambridge Dictionary
We normally use ago with the past simple. We don’t use it with the present perfect:
I received his letter four days ago.
Not: I have received his letter four days ago. Incorrect
- Luskin’s team found that there are now only two habitats with viable populations, down from the 12 thought to have existed 70 years ago.