They are more heavily and most heavily.
While the comparatives heavier and heaviest may be used as adverbs, they do so as forms of the word 'heavy' where it is used (rarely) as an adverb.
Comparative Form- more heavilySuperlative Form- most heavily
The superlative of heavily is "most heavily."
The comparative is greater and the superlative is greatest.
comparative straighter and the superlative the straightest
Comparative - cuter Superlative - cutest
Comparative Form- more heavilySuperlative Form- most heavily
more heavily, most heavily
The superlative is cloudiest; the comparative is cloudier.
comparative : purer superlative : purest
Comparative: older Superlative: oldest
What is the comparative and superlative of Often
The comparative and superlativeforms of grand are: Comparative: grander Superlative: grandest
comparative - merrier superlative - merriest
Comparative: shallower Superlative: shallowest
The comparative is "stricter" and the superlative is "strictest".
comparative = sadder superlative = saddest
The superlative of heavily is "most heavily."