There are a variety of ways to hide the stem of a adjective in its nominative form.
- baburrus, -a, -um (stem barburo-) silly
- levis, -e (stem levi-) fickle
- fēlīx (stem fēlīc-) blessed
- hebes (stem hebet-) dull
However, the majority of adjectives of all stem formations become comparatives and superlatives in the same way: with the addition of -ior (m/f) / ius (n) for comparatives, and the addition of -issimus, -a, -um for superlatives.
- baburrus, -a, -um / baburrior, -ius / barburrissimus, -a, -um
- levis, -e / levior, -ius / levissimus, -a, -um
- fēlīx / fēlīcior, -ius / fēlīcissimus, -a, -um
- hebes / hebetior, -ius / hebetissimus, -a, -um
There are a few things to note here. If an adjective is compared regularly,
- It’s case ending will always have two options (m/f or n) for the comparative and three options (m or f or n) for the superlative, regardless of how many it had for the positive.
- Stress accents will always appear on the penultimate vowel (for comparatives) or the ultimate vowel (for superlatives) of the stem.
babúrrior, baburríssimus / lévior, levísssimus / fēlícior, fēlīcíssimus / hebétior, hebetíssimus
Of course, it can always shift further forward, but never further back. The comparatives declines like so:
The superlatives decline like a regular first/second declension adjectives, regardless of how their positives decline:
The Essential AG: 120, 123-4