According to Barbara Fowler, to most English-speaking people, the use of a double negative, such as, "You cannot have no candy," grates against the ears and conjures up images of a stern English teacher reproaching students with the axiom, "Two negatives equal a positive!"
However, that rule of language has not always existed. In Gesenius' Hebrew Grammar it is stated that "Two negatives in the same sentence do not neutralize each other but make the negation the more emphatic" (Kautzch 1909:483).
There are several instances in the Book of Mormon where a negative word which existed in the original or printer's manuscript has been deleted or changed to a positive word. These examples would point to the Hebrew authorship of the book, as well as enrich meaning of these passages. One such instance is found in Ether 6:25. The second negative (in brackets) was removed and has never been in print:
"And the people would that his father should constrain him, but his father would not; and he commanded them that they should [not] constrain no man to be their king."
[Barbara Fowler, "Double Negatives in the Book of Mormon? Yes! Yes!, in Recent Book of Mormon Developments, Vol. 2, p. 57]