Joe visited me before I had eaten dinner.

[Alice Chu]

Please tell me if my understanding is correct.
1. Joe visited me before I had eaten dinner.
It means Joe visited me before I finished my dinner.
2. Joe visited me before I ate dinner.
It means Joe visited me before I started to eat dinner.

Is the following information correct?
https://learnenglish.britishcouncil.org/grammar/intermediate-to-upper-intermediate/past-perfect
We can also use the past perfect followed by before to show that an action was not done or was incomplete when the past simple action happened.
Examples:
1. They left before I'd spoken to them.
2. Sadly, the author died before he'd finished the series.

The first example means I didn’t speak to them before they left. The action of speaking was not done.
Is my understanding correct?

 

[tedmc]

I think when you have the word "before" used, the past tense is enough. We don't need the past perfect tense when it is clear which action comes first.

 

[emsr2d2]

Please tell me if my understanding is correct.

1. Joe visited me before I had eaten dinner.
It means Joe visited me before I finished my dinner. Not necessarily. He could have arrived before you even started eating your dinner.

2. Joe visited me before I ate dinner.
It means Joe visited me before I started to eat dinner. :tick:

emsr2d2