Enos's father (Jacob) taught him in his language -- which, of course, was reformed Egyptian. (All native Americans spoke reformed Egyptian in 500 BCE.) 1
Enos has a long conversation with the voice, which tells him that he is forgiven through his faith in Jesus, who wouldn't be born for another 500 years or so. And whatever he asks "in the name of Christ," he will receive. God also "covenanted" with Enos, saying he'd preserve his plates with the Lamanites. 5
It wasn't easy for Enos to prophesy among the Nephites because there were exceedingly many other Nephite prophets. But he did his best, speaking with exceeding harshness. 22
Luckily he had read his dad's book so he knew how to talk with "exceedingly great plainness of speech," as you've no doubt already noticed.
Enos ends his little booklet with this:
I rejoice in the day when my mortal shall put on immortality, and shall stand before him; then shall I see his face with pleasure, and he will say unto me.... 27
Which reminds me of this verse from "You and me (but mostly me)" from my all-time favorite musical. (The Book of Mormon).
I've always had the hope,
That on the day I go to heaven.
Heavenly Father will shake my hand and say,
"You've done an awesome job, Kevin!"