Many adjectives form their comparative using the suffix -ji. Adding this suffix triggers a consonant change at the end of the base—a process known as jotation, similar to what we saw with verbs. Additionally, adjectives ending in -ak, -ek, or -ok usually drop this ending before adding the -ji suffix.
Here are the most common consonant changes for these adjectives:
| Base | Mutated | Example | Comparative |
|---|---|---|---|
| b | blj | grub (rough) | grublji |
| d | đ | gladak (smooth) | glađi |
| n | nj | tanak (thin) | tanji |
| st | šć | gust (dense) | gušći |
B, P, M, V to BLJ, PLJ, MLJ, VLJ
When an adjective's base ends in b, p, m, or v, an l is inserted before the j ending. For example, grub (rough) becomes grublji (rougher).
For debeo (thick), the original base is debel-, which loses its e and combines with j to form deblji.
| Linen is rougher than cotton, but it is perfect for summer. | Lan je grublji nego pamuk, ali je savršen za ljeto. |
| If there is no wool, I would buy a thicker material. | Ako nema vune, kupila bih deblji materijal. |
Dropping -ak: Mutations to Đ and NJ
Adjectives ending in -ak, like gladak (smooth) and tanak (thin), drop the -ak before adding the comparative suffix. The remaining consonant then undergoes jotation: the d in glad- mutates to đ (glađi), and the n in tan- changes to nj (tanji).
Remember that comparatives behave like normal adjectives and must match the noun they describe in gender, number, and case (e.g., glađa, tanju).
| Velvet is smoother, but I want a thinner fabric. | Baršun je glađi, ali želim tanju tkaninu. |
| Is silk smoother and thinner than cotton? | Je li svila glađa i tanja nego pamuk? |
Consonant Clusters: ST to ŠĆ
When an adjective ends in the cluster st, the entire cluster mutates. The s becomes š, and the t becomes ć, resulting in šć. For example, gust (dense) becomes gušći.
| This lace is denser, and such a pattern is very expensive. | Ova čipka je gušća, a takav uzorak je vrlo skup. |
| Thicker and denser wool is better for winter. | Deblja i gušća vuna je bolja za zimu. |