Of the Adamic language, we are told that in the days of Adam, their children were taught to read and write, having a language which was pure and undefiled (Moses 6:6). Enoch, once slow of speech, eventually spoke the language masterfully, all nations feared greatly, so powerful was the word of Enoch, and so great was the power of the language which God had given him (Moses 6:31; 7:13). Was this the language of the Jaredites? The issue is debatable because the Jaredites lived over 2000 years after the language originated. No language can remain pure and undefiled for that long, but according to the record the whole earth was of one language, and of one speech (Gen 11:1). Therefore, the language of the Jaredites must have been derived from the pure and undefiled Adamic language.
Joseph Fielding Smith
“It is stated in the Book of Ether that Jared and his brother made the request of the Lord that their language be not changed at the time of the confusion of tongues at the Tower of Babel. Their request was granted, and they carried with them the speech of their fathers, the Adamic language, which was powerful even in its written form, so that the things Mahonri wrote ’were mighty even…unto the overpowering of man to read them.’ (Ether 12:24) That was the kind of language Adam had and this was the language with which Enoch was able to accomplish his mighty work.” (The Way to Perfection, p. 69)