Scholars Royal Skousen and Stanford Carmack have found that much of the English in the Book of Mormon is not that of Joseph’s time, nor of the Bible, in fact it is identified as “Early Modern English” from centuries before.
Stanford Carmack has compared nine key syntactic features that characterize Early Modern English, with their use in the Book of Mormon, the Bible and other 19th century works. These syntactic features include:
The above comparative linguistic evidence indicates that the Book of Mormon was not fashioned in the image of pseudo-biblical writings, or in the image of the King James Bible, or in the image of Joseph Smith’s own language. Nevertheless, Book of Mormon language contains a wealth of archaic forms and structures. This runs counter to the received view of many commentators who have imagined it to be a flawed imitation of biblical language. A variety of substantive linguistic evidence argues that Book of Mormon grammar is deeply and broadly archaic and very different, in one case after another, from both pseudo-biblical grammar and King James style. Many more types of syntax could be given, but the above is sufficient to dismiss the view that pseudo-biblical writings approach the Book of Mormon in archaic form and structure. Those who espouse such a view have ignored crucial syntactic and morphosyntactic evidence.– Stanford Carmack – Is the Book of Mormon a Pseudo-Archaic Text?
How is this compatible with Joseph Smith being the sole author?