Adjectives agree in gender and number with the nouns they modify. The endings of the genders are identical to those of the nouns, including some adjectives which end in ⟨‑e⟩ and may be masculine or feminine, demonstrated here with pitzitu ‘small’ and leve ‘smooth’.
| Singular | Plural | |
| Masculine | pitzit-u lev-e |
pitzit-is lev-is |
| Feminine | pitzit-a lev-e |
pitzit-es lev-es |
Also like the nouns, a final ⟨‑l⟩ in some adjectives becomes ⟨‑u⟩ in the masculine singular, as seen here in umbrau ‘shady’.
| Singular | Plural | |
| Masculine | umbra-u | umbra-lis |
| Feminine | umbra-la | umbra-les |
Masculine singular adjectives ending in ⟨‑cu⟩ have a feminine form ending with ⟨‑cja⟩, as seen here with blancu ‘white’.
Masculine blan-cu blan-cis Feminine blan-cja blan-ces| Singular | Plural | |
| Masculine | blan-cu | blan-cis |
| Feminine | blan-cja | blan-ces |
An unusual development in Braereth, compared to other Romance languages, is the development of participles to have a gendered adjectival form (which is normal) as well as a non-gendered form used exclusively with compound verbs (which is not).
For example, facere ‘to do’ has the past participle faectje ‘done’, used in verb phrases such as L’aou faectje, ‘I have done it’, but Mis deveris soun faectjis, ‘My chores are done’, (with a masculine plural ending). Almost without exception, the uninflected form ends in ‑e, while the inflected forms take the standard masculine, feminine, singular, and plural endings ‑u, ‑a, ‑is, and ‑es.