Student or Learner
Which tense (past simple/present perfect) should be used in the sentence: (during a presentation) As I ________(say) before, there are many people suffering from cancer.
there is my reason for PP: It is a past action when time is not specified
but also for PS: the time can be understood (I mean for a presntation listener.
Both reasons were/has been - (see I do not know again) taken from UE Glossary
I apologise for such a confusing description.
Thanks in advance for your help.
Both forms are possible - it depends on what is going on in the speaker's mind at the moment of speaking.