harp on

US /hɑːrp ɑːn/
UK /hɑːrp ɑːn/
"harp on" picture
1.

rabâcher, insister sur

to talk or write persistently and tediously on a particular subject

:
He keeps harping on about the good old days.
Il ne cesse de rabâcher les bons vieux jours.
I wish she wouldn't harp on my mistakes.
J'aimerais qu'elle ne rabâche pas mes erreurs.