“Sly” (= wily, cunning, sneaky) preferably makes “slyer,” “slyest,” and “slyly.” But some writers use the variant spellings *”slier,” *”sliest,” and *”slily” — e.g.:
o “The land has been creeping slily [read ‘slyly’] out to sea for the last twenty centuries or so.” Steven Moore, “The Beast in the Vatican,” Wash. Post, 15 Sept. 1996, Book World §, at 4.
o “This is not a Michael Jordan-light-up-a-planet smile but something slier [read ‘slyer’], more subtle, the expression of a man who has a private joke.” Michael Farber, “Cat Quick,” Sports Illustrated, 2 June 1997, at 68.
*Invariably inferior forms.
Quotation of the Day: “Many writers think, not before, but as they write. The pen originates the thought. The disadvantage of this, and indeed it is a danger against which the author must be always on his guard, is that there is a sort of magic in the written word. The idea acquires substance by taking on a visible nature, and then stands in the way of its own classification.” William Somerset Maugham, The Summing Up (1938), in Classics in Composition 219, 220 (Donald E. Hayden ed., 1969).