commonest
Commonest is the superlative of common.
"Most common" is the one that is most common.
The comparative form of rude is ruder, and the superlative form is rudest. It is common to form the comparative and superlative of short words like this by adding -er and -est.
Despite the common usage in many places of the world to say things like: "John walks slower than me" the appropriate comparative is "more slowly" and the superlative form is "the most slowly"
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.