present perfect and past perfect, need help please...

Hi I am having a problem using of have and had…
here examples from my class…
One of the strongest eartquakes in this century…HAD HAPPENED… in Anchorage,Alaska,on March 24,1964,at about six o’clock in the evening.When the eartquake…HAD STRUCK…that evening,many families were sitting downt to eat dinner.
As you see I did answer both this examples wrong.they supposed to be

  1. one just:HAPPENED
    2.one:just:STRUCK
    Also with have…
    Almost every part of the world…EXPERIENCED…an eartquake in recent years.
    It was wrong too.
    it suppoesed to be
    HAVE EXPERIENCED
    is there a any easy way to figure the way to sue these thenses correctly.
    Asspecially I have a problem with HAD more than HAVE in sentences or when I use them in my own sentences.
    I belive that HAD can be used when we talk about something in the past already happened while were are talking about something in the past.
    Any help would work
    THNKS MUCH…

One of the strongest earthquakes in this century happened in Anchorage,Alaska,on March 24,1964,at about six o’clock in the evening.When the earthquake struck that evening, many families were sitting down to eat dinner.-- Simple past because a specific past time (3/24/64) is given and because the verbs relate to no other, later past action.

Almost every part of the world has experienced an earthquake in recent years.– Present perfect because the statement applies to ‘recent’ events and because other parts of the world will also likely experience earthquakes in the future (such experiences are not finished yet).

Is there any easy way to figure the way to use these tenses correctly?-- Well, if the verb forms do not exist in your language, then you may find it difficult, but practice will eventually improve you.

I believe that HAD can be used when we talk about something in the past already happened while were are talking about something in the past.-- [b]Not as simple as that. Use of past perfect is for the earlier of two past actions that are related in some way and whose order of occurrence are otherwise unclear:

I ate breakfast when Mabelline arrived.– She saw me eat; I started eating after she came.

But the meaning of ‘when’ can be unclear; it can also mean this, and use past perfect to make it clear:

I had eaten breakfast when Mabelline arrived. – She didn’t see me eat breakfast; I had already finished it.

I ate breakfast before Mabelline arrived - She didn’t see me eating. But I don’t need past perfect because the word ‘before’ makes the order of actions clear.

[/b]

Thanks alot Mister Micawber.
It helped alot.Also,I figure out that it might be more usefull if I keep tracking with my language back and forward between english tenses.I think that would help much more than study only english grammar itself.
Thnks again…by the way I see that you are waering a Cub(Chicago Cubs Baseball) hat on your profile picture,are you from Chicago? I used to live there 3 years great city ever…
THNKS SO MUCH again.

Good eye! That’s my mother’s cap-- she was a big Cubbies fan.