Should, in the second and third persons, expresses duty, and the idea of the author was, to express an event, under a condition, or a modest declaration; he should have used would.
"There is not a girl in town, but let her have her will in going to a mask, and she shall dress as a shepherdess."——Spect. No. 9.
Shall, in this example, expresses command, an idea very different from the author's meaning.
"Think what reflection shall most probably arise."——Blair, Serm. 9.
"A person, highly entertained at a play, shall remember perfectly the impression made on him by a very moving scene."——Nugent's Trans. of Condillac, p. 1. s. 1.
I would just remark here, that the errors in the use of the auxiliary verbs before mentioned, are not English; that they are little known among the inhabitants of South Britain, and still less among their descendants in New England. This is a new proof of the force of national customs. I do not remember to have heard once in the course of my life, an improper use of the verbs will and shall, among the unmixed English descendants in the eastern states.
But of all the errors or inaccuracies in speaking or writing the English language, the most numerous class appear in the improper use of verbs in the subjunctive mode. Not only illiterate men, but authors of the first rank, often use the present tense for the future, the future for the present, and the past for both.
"If any member absents himself, he shall forfeit a penny for the use of the club, unless in case of sickness and imprisonment."——Rules of the Two Penny Club, Spect. No. 9.
"If thou neglectest or dost unwillingly what I command, I'll rack thee with old cramps."——Temp. act 1. s. 4.