Itchier is the comparative form and itchiest is the superlative form.
Comparative: My new shoes are itchier than my old shoes.
Superlative: Those cheap shoes you can get at the local department stores are the itchiest shoes I've ever tried.
The comparative and superlativeforms of grand are: Comparative: grander Superlative: grandest
comparative = sadder superlative = saddest
The comparative is "stricter" and the superlative is "strictest".
Comparative: shallower Superlative: shallowest
Comparative: thinner Superlative: thinnest
comparative : purer superlative : purest
Comparative: older Superlative: oldest
Dative; Early Comparative; Earlier Superlative; Earliest
The comparative and superlativeforms of grand are: Comparative: grander Superlative: grandest
comparative - merrier superlative - merriest
comparative = sadder superlative = saddest
The comparative is "stricter" and the superlative is "strictest".
Comparative: shallower Superlative: shallowest
The comparative is greater and the superlative is greatest.
comparative straighter and the superlative the straightest
Comparative is more and superlative is most.
comparative is calmer superlative is calmest