Big topics, Need2CU.
One view from Strunk's The Elements of Style:
Shall. Will. In formal writing, the future tense requires
shall for the first person,
will for the second and third. The formula to express the speaker's belief regarding a future action or state is
I shall;
I will
expresses determination or consent. A swimmer in distress cries, "I
shall drown; no one will save me!" A suicide puts it the other way: "I
will drown; no one shall save me!" In relaxed speech, however, the
words
shall and
will are seldom used precisely; our ear
guides us or fails to guide us, as the case may be, and we are quite
likely to drown when we want to survive and survive when we want to
drown.
One view from
Guide to Grammar and Writing:
Uses of Will and Would
In certain contexts, will and would are virtually interchangeable, but there are differences. Notice that the contracted form 'll is very frequently used for will.
Will can be used to express willingness:
- I'll wash the dishes if you dry.
- We're going to the movies. Will you join us?
It can also express intention (especially in the first person):
- I'll do my exercises later on.
and prediction:
- specific: The meeting will be over soon.
- timeless: Humidity will ruin my hairdo.
- habitual: The river will overflow its banks every spring.
Would can also be used to express willingness:
- Would you please take off your hat?
It can also express insistence (rather rare, and with a strong stress on the word "would"):
- Now you've ruined everything. You would act that way.
and characteristic activity:
- customary: After work, he would walk to his home in West Hartford.
- typical (casual): She would cause the whole family to be late, every time.
In a main clause, would can express a hypothetical meaning:
- My cocker spaniel would weigh a ton if I let her eat what she wants.
Finally, would can express a sense of probability:
- I hear a whistle. That would be the five o'clock train.