Tallest is the superlative.
smallest is the superlative. (est is the standard superlative ending._
bigger is the comparativebiggest is the superlative
The superlative of clear is clearest.
Fattest is the superlative of fatter.
most cost-efficient
more efficient, most efficient
most cost-efficient
More efficient and most efficient are the comparative and superlative forms of "efficient".
The superlative of successful is "most succesful."
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.
"Studying" is not a superlative, as it is not an adjective. "Most studious" is a superlative of "studious."
"Bib" is a noun and, as such, does not have a superlative form.
most superlative is the superlative form of superlative
Tallest is the superlative.
superlative of quiet