quicker, quickest
Quickest.
Quickly is an adverb The comparative form of quick is more quicker. The superlative form of quick is quickest.
Quickest.
quickest
Quickest
quicker, the quickest
quicker/quickest
quicker, quickest
quicker, the quickest
Rabbit
The comparative degree of "quick" is "quicker," and the superlative degree is "quickest." These forms are used to compare the speed of two or more subjects, with "quicker" indicating a higher degree of quickness and "quickest" indicating the highest degree among three or more subjects.
Sleep is a noun and does not have a superlative. Sleepy is an adjective and the superlative is "sleepiest."