Shall is not used as plain future much. Let's see what it is used for.

MurielB a écrit:Hi Gérard
For me all this is fairly simple The Amerian English doesn't use shall much (I think) while British traditionally use shall to express determination or intention on the part of the speaker or someone other than the subject of the verb - I have found a lot of interesting things in "La grammaire de l'anglisciste" . I will try to write it another time.

Hi Gérard
Let's translate  what "La gramaire anglaise de l'étudiant " says into English 

"Shall" is not used  as "plain future" much. (in America, Scotland Ireland they only use will ) I will help you if you like.
 Shall  implies that the person's will is not present or limited. It is really what you have to remember.

Shall  is used to ask for an advice (British English)
Shall we help you ?
Shall we go to the pictures ?

You can add shall I ( shall we) to imperative or future 1 personne.
Let's have a cup of tea shall we ?
We'll go for a walk after lunch shall we ?=> It's probably what you remember, Gérard.
for the other persons you have will. Open the door for me will you ?

Shall is used in a solemn and formal way for command, promise  or threat
You shall have your fur-coat for Christmas darling
Your orders shall be obeyed
It shall be as you say
You shall leave the room at once (I will check that you have done it and will do my best for that) ( "you will leave the room at once " would mean that I refuse to accept your disobedience  )

Shall is used in official regulations
The boys shall wear their uniforms every day
whereas when there is a threat it is will : Trespassers will be prosecuted

Shall is used for prophecies
And the dead shall rise
If you don't change your behaviour you shall rue it

Shall is used in negative form for interdiction (archaic form)   you shalt not kill

Let's hope this post will be useful