most cost-efficient
most cost-efficient
The superlative of efficient is "most efficient."
more efficient, most efficient
the superlative form for movingly in most movingly
The superlative form of ancient is ancientosity
The superlative form of clean is "cleanest".
The superlative form of clean is "cleanest".
comparative - merrier superlative - merriest
The comparative form of cloudy is "cloudier". The superlative form is "cloudiest".
The superlative form of genuine is more genuine.
"Older" is the comparative form of old. The superlative form is oldest.
The superlative form of sorrowfully is most sorrowfully.