Can you tell me when I must use this words, and the meaning of each one?

would
should
will
shall
have
have been
had
and had been

tks.

Talvez alguns exemplos lhe ajudem:

I would work - Eu trabalharia;
I should work - Eu deveria trabalhar;
I will work - Eu trabalharei;
I shall work - Eu (estou certo que) vou trabalhar;
I have worked - Eu trabalhei;
I have been working - Eu tenho estado trabalhando;
I had worked - Eu tinha trabalhado;
I had been working before you arrived - Eu estava trabalhando antes de você chegar.

obrigado me ajudou muito.

Please note that shall and will in English are conjugated correctly as follows:

1st person singular and plural: I shall and we shall = future. Eu trabalharei
but
2nd person singular and plural you will = future
3rd person singular and plural he, she, it will/they will = future

but

I will Eu (estou certo que) vou trabalhar
you shall
he,she, it shall
we will
you will
they shall
= a command

This is the correct way. However in normal usage you will hear the contractions I'll and we'll hence you will not often hear it (apart from in questions). Also sometimes people will not adhere to this correct usage. If you are aiming to pass an exam you are best off following the correct form.