Although it is supposed to be a 19th century translation of something that the Mormons claim was written by several people over a period of about a thousand years (from 600 B.C. to approximately 400 A.D.) the language is strictly in the 15th century Elizabethan style. Since the Egyptians, Hebrews and Aramaics didn't speak 15th century Elizabethan English, and since the 19th century Americans didn't talk that way either, one wonders why Smith found that such a style of wording, using the biblical yeas and nays, and thees and thous, was a direct translation of something a few thousand years old. Undoubtedly, Smith felt that by imitating the biblical language (King James Version), he would be able to give it a more mystical and religious air, and thereby help make his newly concocted writings more plausible and acceptable. The Book of Mormon further follows the format of the Christian and Jewish Bible. The story it tells, however, is altogether different.
The Book of Mormon allegedly gives an account of a group of people of the Tribe of Manasseh who left the city of Jerusalem in the year 600 B.C., and some eight or ten years later sailed a ship across the Indian and Pacific oceans to the Western Hemisphere. It then goes on in an exceedingly boring and tedious narration of the trials and tribulations, successes and failures, of the descendants of these people, until finally the remnant of them are exterminated by their enemies in the year 421 A.D. on a hill in what is now New York State, where Joseph Smith claimed to have found their records some 1400 years later.