[Grammar] I didn't see/I hadn't seen

[Ghyousef]

Which one is more correct to say
The girl in blue was a complete stranger to me because ( I didn't see/ I hadn't seen ) her before.
If both are correct do they have the same meaning if not. What does each one mean?

 

[emsr2d2]

Which one is [strike]more[/strike] correct​? [STRIKE]to say[/STRIKE]

The girl in blue was a complete stranger to me because no bracket necessary I didn't see/I hadn't seen no bracket necessary her before.

If both are correct, do they have the same meaning? If not, what does each one mean?

Welcome to the forum. :hi:

Only "I hadn't seen her before" works there.

Note my corrections above, and that I have changed your thread title so it includes the words you are querying.