Question

Hey, i have lots of difficult with this time, if someone could help me i would be grateful

Answer 1

When you are talking about two actions in the past, the one that occurred first should be in the Past Perfect tense and the latter, in the Simple Past tense.

Example: The train had left (Past Perfect) when we arrived(Simple Past) to the railway station. The action of leaving, performed by the train, occurred before we arrived to the railway station. 

Answer 2

   first action                 second action      

  past perfect                  simple past