The distinctions between will and shall are now strictly observed only by precise speakers. Shall is becoming less common especially with the second and third person pronouns. With first person pronouns, however, shall is still being used to indicate the simple future.
In conversation people generally use the shortened form ’ll.
- We’ll have a party tomorrow.
- I think I’ll send him a letter.
In these sentences, according to strict grammatical rules, one has to use shall. But ’ll may be the contraction of either shall or will. However, research has shown that most people consider ’ll to be a contraction of will, which proves that in actual usage will has been replacing shall.
Instead of using shall with second and third person pronouns to express a command, promise, threat or determination, people often use other verbs and forms of expression.
For example, instead of saying ‘You shall go at once’, people often say:
- You will have to go at once.
- You are to go at once.
- You must go at once.