A point worth remembering here is that languages treat the future quite distinctively. Some languages have a future tense, e.g. Tagalog in the Philippines, and it is fair to include Russian and French, while others like Eskimo have a near future form, a far future form and so on. English does neither of these but has many expressions that imply a future action. Will is for predictions, must for inescapable events, should for probable events; the progressive is for things begun, to be finished after R, hence for future events already begun, while simple verbs (the so-called 'present tense') are for states of affairs without a finish point F, and for events not yet begun but already fact.