Comparison

Slovenian, like English, forms comparatives in two ways:

1. the comparative is formed with the word bolj (more), and superlative with najbolj (most)

bel bolj bel najbolj bel

2. the comparative is formed with suffixes, which are -ejssi - si and -ji; the superlative is formed by adding the prefix naj- onto the comparative. Polysyllabic adjectives form the comparative by means of ejssi (ljubezniv - ljubeznivejssi). but memorize the following forms:

boga't  

-bogatéjssi
do'lg
-da'ljssi
drag
-drazzji
dêbel   
-debeléjssi
do'ber
-bo'ljssi
globo'k
-glo'blji

krêpek

-krepkéjssi
lép
-lépssi
lahek
-la'zzji
no'v
-novéjssi
ma'jhen
-ma'njssi
nizek
-nizzji
pocéni
-cenéjssi
mla'd
-mla'jssi
o'zek
-o'zzji
réven
-révnejssi
sla'b
-sla'bssi
vélik
-véccji
sta'r
-staréjssi
ssiro'k
-ssirssi

viso'k

-vissji

Remember also the following forms for comparatives of adverbs:

blizu
-blizzje ali blizze
dôbro
-bo'lje
da'lecc
-dalje
zelo'
-bo'lj
do'lgo
-da'lj
veliko
-vécc
ma'lo
-ma'nj
ra'd (ra'da, ra'do)
-ra'je ali ra'jssi

Cf. These are typical relations:

Ana je lepa kot njena mama - Ana je lêpssa kot njena mama (or od njene mame). Instead of kot, kakor and ko are also used.

Aleksandra Ceferin, Thezaurus (Melbourne 2000)