prettier
prettiest
For the adjective "pretty" -- prettier is the comparative, and prettiest is the superlative.
prettier
Prettier the prettiest
Perhaps you mean the comparative form: the comparative form of the adjective pretty is prettier. (The superlative form is prettiest, but comparative sounds more like cumulative.)
Neither. Pretty is the positive degree. The comparative is prettier; the superlative is prettiest.
prettiest
prettier, prettiest
prettier, prettiest
prettier, prettiest
Cute, beautiful, gorgeous
prettier, prettiest
prettiest, prettier