Can anyone tell me why is not the Present Perfect tense used in the phrase "as far as I understand / understood" (I guess both are possible, correct me if I am wrong)?
- This phrase means that I understood something in the past, and I still understand it now, so it refers to an interval of time up to now.
- The fact that someone understood something is much more important than when or where it was done.
- It has strong connection to the present: something, happening at the moment of speech, probably depends on whether someone understood / understands something or not.
And yet it seems that nobody says "as far as I have understood". Why?