An is still vulgarly used in the sense of if. "An please your honor," is the usual address of servants to their masters in England; tho it is lost in New England. But a word derived from the same root, is still retained; viz. the Saxon anan, to give; which is sometimes pronounced nan, and sometimes anan. It is used for what, or what do you say; as when a person speaks to another, the second person not hearing distinctly, replies, nan, or anan; that is, give or repeat what you said. This is ridiculed as a gross vulgarism; and it is indeed obsolete except among common people; but is strictly correct, and if persons deride the use of the word, it proves at least that they do not understand its meaning.
Unless, lest and else, are all derivatives of the old Saxon verb lesan, to dismiss, which we preserve in the word lease, and its compounds. So far are these words from being conjunctions, that they are, in fact, verbs in the Imperative mode; and this explanation serves further to lay open the curious structure of our language. For example:
"Unless ye believe ye shall not understand," may be thus resolved; "Ye believe; dismiss (that fact) ye shall not understand." Or thus, "Dismiss ye believe, (that circumstance being away) ye shall not understand." Thus by analizing the sentence we find no Subjunctive mode; but merely the Indicative and Imperative.
"Kiss the Son, lest he be angry," is resolvable in the same manner: "Kiss the Son, dismiss (that) he will be angry." Else is used nearly in the same sense, as in Chaucer, Freres Tale, 7240:
"Axe him thyself, if thou not trowest me,
Or elles stint a while and thou shalt see."
That is, "If thou dost not believe me, ask him thyself, or dismissing (omitting that) wait and thou shalt be convinced."
Though, or tho, commonly called a conjunction, is also a verb in the Imperative Mode. It is from the verb thafian or thafigan, which, in the Saxon, signified to grant or allow. The word in its purity is thaf or thof; and so it is pronounced by many of the common people in England, and by some in America.
"Tho he slay me, yet will I trust in him," may be thus explained; "Allow (suppose) he should slay me, yet will I trust in him." That this is the true sense of tho, is evident from another fact. The old writers used algife for although; and its meaning must be nearly the same.