The Pluperfect is a kind of setting. It’s setting something up. But instead of telling you what’s going on right now, it’s telling you what has already been completed. You can’t really have it all on it’s own. If you received a text from someone that said, “I had arrived,” that wouldn’t make sense. It’s grammatically incorrect. You’re still needing the thing that happens after you arrived.
Student Example: Quintus de arbore ceciderat. Crus ruptum est.
Problem: He is already done falling when “crus ruptum est.”
Corrected: Crus ruptum erat. Ploravit.
Student Example: Sol luxerat. Pastor ovem quaesivit.
Problem: The sun has already finished shining. It’s dark out.
Student Example: Vir pocula vino impleverat cum Marcus in atrium cucurrit et pocula fregit.
Commentary: We know there is wine all over the place because impleverat assumes the cups were already full when they were knocked over.
Student Example: Flores a puella carpti erant; ea vendere volebat.
Problem: It’s incomplete. There is a pluperfect and an imperfect. She had picked the flowers, and she wants to sell the flowers (on going), now we need a main action. Example: Sed Romani oppugnaverunt (eam).