Most stressed. E.g.: "Of all the students in the library, Karen was clearly the most stressed about finals."
Sleep is a noun and does not have a superlative. Sleepy is an adjective and the superlative is "sleepiest."
The superlative for willing would be "most willing." There is no one-word superlative.
"Bib" is a noun and, as such, does not have a superlative form.
"Studying" is not a superlative, as it is not an adjective. "Most studious" is a superlative of "studious."
most superlative is the superlative form of superlative
Tallest is the superlative.
superlative of quiet
bigger is the comparativebiggest is the superlative
smallest is the superlative. (est is the standard superlative ending._
The superlative of chunky is chunkiest
The superlative for "older" is "oldest."
The superlative of "shine" is "shiniest."