Comparatives and Superlatives Grammar 2

Adjectives of more than two syllables form the comparative with more and the superlative with most. For example: useful - more useful, most useful.
Normally, two-syllable adjectives ending in letter -Y have both options. In other words, you can say "Cindy is more friendly than Tom" or "Cindy is friendlier than Tom".
Some adjectives such as narrow, stupid, gentle, clever and some others take both options too. That is, you can say "She is the cleverest student" or "She is the most clever student".
To sum up, you can use -er and -est or more and most to form the comparative and the superlative, but only in these cases.