Periodically writes about English writer and is contrite (7)
I believe the answer is:
repents
'is contrite' is the definition.
(I've seen this in another clue)
'periodically writes about english writer' is the wordplay.
'periodically' indicates alternate letters (letters must be selected 'every so often').
'about' is an insertion indicator.
'english' becomes 'E' (abbreviation).
'writer' becomes 'pen' (something which writes).
The alternate letters of 'writes' are 'rts'.
'e'+'pen'='epen'
'rts' placed around 'epen' is 'REPENTS'.
'and' is the link.
(Other definitions for repents that I've seen before include "Turns away from evil" , "Feels remorse for, sin perhaps" , "Present (anag.)" , "Feels sincere remorse" , "Expresses sorrow for sin" .)