The comparative form of "thin" is "thinner," and the superlative form is "thinnest." These forms are used to compare the thickness of two or more objects or individuals. For example, you might say, "This book is thinner than that one," or "She is the thinnest person in the group."
thinner
thinner, thinnest
thinner, thinnest
thinner, thinnest
The comparative is greater and the superlative is greatest.
Comparative: thinner Superlative: thinnest
thinner
thinner, thinnest
thinner, thinnest
thinner, thinnest
thinner, thinnest
thinner, thinnest
There is no procedure (except maybe looking it up in the dictionary, if you don't know on your own). The comparative of thin is thinner; the superlative is thinnest.
Dative; cloudy Caomparative; cloudier Superlative ; cloudiest
comparative : purer superlative : purest
Comparative: older Superlative: oldest
The comparative and superlativeforms of grand are: Comparative: grander Superlative: grandest