2. Use the superlative of gravis.

3. Accusative. In a comparison the noun after quam is in the same case as the one before it.

N.B. Beginning at this point, the [selections for reading] will be found near the end of the volume. (See [p. 197].)

[ LESSON LIV]
IRREGULAR COMPARISON OF ADJECTIVES · THE ABLATIVE WITH COMPARATIVES WITHOUT QUAM

[307.] The following six adjectives in -lis form the comparative regularly; but the superlative is formed by adding -limus to the base of the positive. Learn the meanings and comparison.

PositiveComparativeSuperlative
facilis, -e, easyfacilior, -iusfacillimus, -a, -um
difficilis, -e, harddifficilior, -iusdifficillimus, -a, -um
similis, -e, likesimilior, -iussimillimus, -a, -um
dissimilis, -e, unlikedissimilior, -iusdissimillimus, -a, -um
gracilis, -e, slendergracilior, -iusgracillimus, -a, -um
humilis, -e, lowhumilior, -iushumillimus, -a, -um

[308.] From the knowledge gained in the preceding lesson we should translate the sentence Nothing is brighter than the sun

Nihil est clārius quam sōl

But the Romans, especially in negative sentences, often expressed the comparison in this way,