Pretty is also used by Prescott, Franklin, De Quincey, Defoe, Dickens, Kingsley, Burke, Emerson, Aldrich, Holmes, and other writers.
Mighty.
The adverb mighty is very common in colloquial English; for example,—
"Mighty well, Deacon Gookin!" replied the solemn tones of the minister.—Hawthorne.
"Maybe you're wanting to get over?—anybody sick? Ye seem mighty anxious!"—H. B. Stowe.
It is only occasionally used in literary English; for example,—
You are mighty courteous.—Bulwer.
Beau Fielding, a mighty fine gentleman.—Thackeray.
"Peace, Neville," said the king, "thou think'st thyself mighty wise, and art but a fool."—Scott.
I perceived his sisters mighty busy.—Goldsmith.