When do We Use Past Perfect?

We use Past Perfect to talk about things that took place:

before something else in the past
Example: Jessica discovered Justin had lied to her.  (note the form: HAD + Past Particle)
         So here we have two actions: 1. Jessica discovered
                                                       2. Justin had lied.

        What happened first?      Justin lied to Jessica.
        What happened then? Jessica discovered the truth.
        What is happening now? You are reading this lesson about  Justin and Jessica
        because you want to use Past Perfect perfectly well. :-)

                  (Past Perfect)                                           (Past Simple)                      (Present)        
_____1. Justin had lied to her__________ 2. Jessica discovered 1________Now____

        Jessica discovered Justin had lied to her.

So, we use Past Perfect to talk about a past situation or activity that took place before
another past situation or activity.

during a period  before and event in the past:
I had been feeling anxious all day, but the feeling vanished as soon as I got the exam result.
     
What happened first? : I had been feeling anxious (I felt anxious not just a moment but for a period
of time in the past.)

What happened then?: I got the exam results.

             (Past Perfect Continuous)                             (Past Simple)                                                     
_____1. I had been feeling anxious________ 2. I got the exam results and the feeling vanished______Now

I had been feeling anxious all day, but the feeling vanished as soon as I got the exam result.

Exercise 

Follow this blog