Person revered pens poem and riddle (4)
I believe the answer is:
sift
'riddle' is the definition.
(I've seen this before)
'person revered pens poem' is the wordplay.
'person revered' becomes 'st' (I am not sure about this - if you are sure you should believe this answer much more).
'pens' is an insertion indicator.
'poem' becomes 'if' (I've seen this in other clues).
'st' placed around 'if' is 'SIFT'.
'and' acts as a link.
Can you help me to learn more?
(Other definitions for sift that I've seen before include "Remove lumps from, eg, flour" , "Make fist of filter" , "Separate by passing through fine mesh" , "Examine (eg evidence) discriminatingly" , "Use fist to pass through perforated container" .)