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.
Skousen and Carmack show that the Book of Mormon contains word meanings and phrases which are unattested in Joseph’s time yet commonly found in the centuries before. Some of the words used in the Book of Mormon which are not found in the Bible or any nineteenth-century literature are:
Why did Joseph Smith use these words which were unattested in his time or the Bible? Where did the words come from? Doesn’t this show Joseph was not the author?