Few will ever forget the words spoken by Winston Churchill in June 1940
under the thickening shadow of Nazi aggression:
“We shall not flag or fail. We shall go on to the end. We shall fight
in France, we shall fight on the seas and oceans, we shall fight with
growing confidence and strength in the air, we shall defend our island,
whatever the cost may be. We shall fight on the beaches, we shall fight on
the landing grounds, we shall fight in the fields and in the streets, we
shall fight in the hills; we shall never surrender.”
In a moment of such immortal conviction, none would have thought to
question whether Churchill was using the correct auxiliary verb to express
his nation’s resolve. His words are as powerful and inspiring today
as they were almost 80 years ago.
Notwithstanding, if English teachers of the day had reviewed
Churchill’s speech before he gave it, they would have alerted the
leader to the usage of shall versus will:
• To express a belief regarding a future action or state, use shall. To express determination or promise (as Churchill was), use will. As a further example, a man who slips from a roof with no one around and hangs on to it by his fingers will cry, “I shall fall!” A man who climbs to a roof in order to fall from it will cry, “I will fall!”
• To simply communicate the future tense (without emphasis on determination, promise, or belief) in formal writing, use shall for the first person (I, we) and will for the second and third persons (you, he, she, they):
I shall go to the store tomorrow. They will go to the store tomorrow.
Such established grammatical strictures once made discerning shall from will easy for English users. Through the
years, however, the words’ functions have blurred; in common writing
and speech, they are often interchangeable and seldom precise.
Adding to the matter, style and grammar sources offer differing views on
when to use shall or will. The Harbrace College Handbook asserts the auxiliaries are transposable
for the first, second, and third person. It also declares will is more common than shall; shall is used
mainly in questions (Shall we eat?) and might also be used in
emphatic statements (We shall overcome.).
It further upholds the teaching of Churchill’s day to use shall in the first person and will in the second and
third to express the simple future tense or an expectation: I shall stay to eat. He will stay to chat with us.
To communicate determination or promise, however, it slightly departs from the Queen's classic English. Rather than always use will, it flips its order for the future tense or an expectation (i.e., will in the first person; shall in the second and third). Grammatical form for those intent on falling from a roof would thus be "I will fall!" (first person) or "You shall fall!" (second person).
Perhaps more pliable and contemporary, The Rinehart Guide to Grammar and Usage suggests the words’
loose and inconsistent usages have rendered them identical. This other
book’s only discernible guideline is that shall is the more
stuffy of the two auxiliaries; it seldom appears anymore except in a
question or with the first-person I or we.
Moving in yet another direction, The Associated Press Stylebook directs us to use shall to express determination in all
circumstances (I shall win the election. You shall win the election. She shall win the election.). It also points out that either will or shall may be
used in the first person when not emphasizing determination: I shall stay to eat. I will stay to chat with them. For the second
and third persons, use will unless emphasizing determination: He will stay to eat but They shall win the election.
The Chicago Manual of Style
puts forth that will is the auxiliary verb for the future
tense, which conveys an expected action, state, or condition (Either he or I will stay to eat). It further suggests that will is now more common and preferred than shall in
most contexts. In American English, it says, shall can replace will, but the most typical usage will be in first-person
questions (Shall we stay to eat?) and in statements of legal
requirement (You shall appear in court three weeks from today.) It further specifies that must is a better word than shall for statements of legal requirement.
In his seminal book The Careful Writer, Theodore M. Bernstein says
the heck with it all:
A speech such as Churchill’s proves we can override any
grammatical doctrine for shall or will.
He notes that if anything, will appears to be the favored
auxiliary in most declarative sentences and shall is used for a
touch of formality. In other words, no matter when or where you use shall or will, you’re probably right.
We agree—but you don’t have to. If you prefer strict and clear
guidelines, they exist: Simply choose your stylebook. If on the other hand
you believe shall and will should be free to stand in for
each other, you already have such privilege to swap.
So let’s write as we will, shall we?