This is where it gets confusing for people. When writing in present tense about something that happened in the past. This is where past perfect comes into play when writing in past tense, and past tense comes into play when writing in present tense.

Examples. Usually the easiest way to figure things out.

PRESENT TO PAST

She flips her phone open and dials the number quickly, waiting for it to ring and the person to answer. Once the line picks up, she starts without so much as a “Hello.”

“You’ll never guess what happened to me.”

“What?” her friend replies.

“I just went online and this chick totally wrote a horrible review. I read it and sat here for twenty minutes, bawling my eyes out. I don’t even think she read the book!”

*** See how there’s a switch from present tense to past when the character is talking about something that happened (also see this sentence). It adds to the depth of the scene.

PAST TO PAST PERFECT

Rusty sat at the desk, reading over what she had written. Her journal from six years before was filled with scrawls and drawings that made little to no sense to her. She barely remembered even writing those words down. But she had written them. Time and time again, she had written about the little boy, Charlie, who she had thought she was in love with and how she had hated her mother for something stupid that had happened.

So much had changed from them to now.

Now she was happily married to Jimmy and had a fantastic relationship with her mother. Time changed so much in her life that she could barely even remember when everything seemed to be going wrong.

*** Past perfect has to do with setting something in the past in already past tense. The “she had written” is past perfect. This one is a bit trickier to master. I still screw it up!!