甚麼是Past Perfeet Tense?

The Past perfect tenseis formed by had+a past participle.It is used:-
(1) To speak of an action concluded before a certain time in the past or before the time of the occur of another action(the simple past) and continuing into it,eg:-
Monster had learned Japanese before he came to Japan.
When he got to the bookshop the cartoon comic had already sold.
Monster didn't go to the cinema because he had already seen the comic-cartoon.
All refer to past perfect.and more usage:-
(2)To express a past condition or supposition with an implied negative,eg:-
If monster had known that you wanted the comic book, he would have sent it
If he had worked one more comic-cartoon, he would have published the 99 versions.
If only he had known that you wanted to meet him,he would have stayed in Tokyo.
(3)Conjunctions which the Past Perfect Tense associated are:-before,when,after,once,as soon as,until, eg:-
He came to the theatre before I had finished the cartoon-comic.
When/After/the cheering had died down, the author began his speech.
Once/As soon as/new of the retirement had been given, the world went crazy.
It was not until he had blinded that he understood the retirement was needed..

1. To express thatsomething happened before a specific time in the past.e.g. I have a good knowledge of the Canadian Rockiesbecause I had visited there many times.2. Use it to expressthat something began in the past and continued up until another action in thepast.e.g. The employees feltodd about the changing of the policies because they had another better set ofregulations for over ten years.3. use it to refer to a lack of experience at a specific time.e.g. I had never experienced loaning procedures in such a tediousway before I bought this condominium.

2013-12-26 02:05:13 補充：
#2 and #3's explanations are referenced from www.google.com. However, all of the sentences are composed by myself.

早前我上載了一些錄像在Youtube，解釋一些基本的文法規則，這個錄像正正回答你的問題，希望可以幫到你。
https://www.youtube.com/watch?v=EvC5ID9iCCM

Past Perfeet Tense 過去完成式

指係過去某個時間'完成/經驗/持續/結果''

句型:had+過去分詞(pp)

例: I had just finished it when she came to my office.
當她來到我的辦公室時,我剛好完成了那個工作

( 她進到辦公室是過去既事件,我完成工作係之前既事)

p.s過去完成式,時間點係指[過去既事件],因此可以明確指出[過去]既詞語一齊出現,即係可以同when/then/yesterday等時間副詞一齊用~

應該是 past perfect tense. 這條問題不成立

Past perfect tense is:
Had +p.p.