PAST PERFECT VS. PAST SIMPLE

Hello students of 3º ESO!!!!

Today we're going to deal with the second part of the gramar of unit 8. This parts deals with the differences between the Past Perfect and the Past Simple.

Past perfect vs. past simple

We can use the past perfect and the past simple to show the order of two past events. The past perfect shows the earlier action and the past simple shows the later action.

When the police arrived, the thief had escaped.

It doesn't matter in which order we say the two events. The following sentence has the same meaning.

The thief had escaped when the police arrived.

Note that if there's only a single event, we don't use the past perfect, even if it happened a long time ago.

The Romans spoke Latin. (NOT The Romans had spoken Latin.)

Past perfect with before

We can also use the past perfect followed by before to show that an action was not done or was incomplete when the past simple action happened.

They left before I'd spoken to them.
Sadly, the author died before he'd finished the series.

Adverbs

We often use the adverbs already (= 'before the specified time'), still (= as previously), just (= 'a very short time before the specified time'), ever (= 'at any time before the specified time') or never (= 'at no time before the specified time') with the past perfect. 

I called his office but he'd already left.
It still hadn't rained at the beginning of May.
I went to visit her when she'd just moved to Berlin.
It was the most beautiful photo I'd ever seen.
Had you ever visited London when you moved there?
I'd never met anyone from California before I met Jim.

If you still have doubts about it, you can read an explanation in Spanish in the following link:

http://www.blueblocnotes.com/grammar/past-perfect-tenses/past-perfect-vs-past-simple 

Also, you can comment your doubts on this post.

Take care!!!!