Future tense forms are usually made with will or shall. In British English, both will and shall are possible with first person pronouns (I and we). There is little difference of meaning.
- I will do it. OR I shall do it.
- We will come. OR We shall come.
Shall is not normally used with second and third person pronouns or nouns to make simple predictions about future.
- She will come with you.
- You will hear from us soon.
- The trees will bear fruit in two years.
- The cat will catch the mouse.
- They will have what they want.
In American English, shall is not normally used. Instead, American speakers use will with all pronouns and nouns.
While speaking I will and we will are pronounced as I’ll and we’ll. Note that I shall and we shall are also pronounced exactly the same: I’ll and we’ll.
Will is sometimes used with I and we to show determination.
- We will find the truth. (= We are determined to find the truth.)
Shall can be used with second and third person pronouns to express ideas such as commands, orders etc. Note that this use of shall is very rare.
- He shall take up the responsibility. (= It is an order.)