ceigered:
Mi parolintis - I had spoken, I had been speaking. <- this is more for a narrative sense - if you're talking in past tense, e.g. like in a novel, and you want to show that this is even MORE past tense than what you're writing in (e.g. had already happened) then use this one. Only, though, if you really need to, like if it wouldn't make sense at all with just parolis.

Adding to that, don't underestimate the usefulness of adverbs. The seeming necessity of a pluperfect can usually be averted by adverbs.

Bennon:
Adding to that, don't underestimate the usefulness of adverbs. The seeming necessity of a pluperfect can usually be averted by adverbs.

Now that you mention that, that's probably the most useful thing about all these endings, using them in adverbs and adjectives. (e.g. Sidante, mi legis libron - Sitting, I read a book).