Грамматика русского языка
Он три раза забывал о дне рождения жены.
This is the sentense from my textbook.What I'd like to point out is "забывал".In this case,the writer chose "забывал" because this action has been done(3 times).But I've read one grammar book and it says,you can think of 3 times as one action and so can use "забыл".
Is this correct,and which is more frequently used?