"More forgetful" is the comparative form of forgetful.
"Most forgetful" is the superlative form.
There is no such word as "forgetfuller".
More forgetful
The comparative form of longest is longer.
The comparative form of easy is easier, and the superlative form is easiest.
The comparative form of gloomy is gloomier, the superlative form is gloomiest.
The comparative form of noisy is Noisier
More important is the comparative form, and most important is the superlative form.
The word forgetful is an adjective.The noun form of the adjective forgetful is forgetfulness, a common noun. There is no proper noun form.
The comparative form of dreamy is dreamier
The comparative form of many is more
The noun form of the adjective forgetful is forgetfulness.
The comparative form of "softly" is "more softly."
"Truer" is the comparative form of true.
The comparative form of handsome is handsomer
The comparative form of solid is solider
The comparative form of "central" is "more central."
The comparative form of good is better.
The comparative form of full is fuller
The comparative form of sunny is sunnier.