[Chris87]

Sorry for keeping to ask questions, I've the last one left, the Past Perfect Tense is used for things happened in the past and that were still going on, egg:

-I had been going home before I met my friend.

But what if I specify the time, let's guess I met my friend yesterday, it should be:

-Yesterday, I had been going home before I met my friend.

or it should be:

-Yesterday, I was going home before I met my friend.

If I put the time it doesn't change the Past Pefect Tense or it does?