Castúo is the generic name for the dialects of Spanish spoken in the autonomous community of Extremadura, in Spain. Not to be confused with Extremaduran, a language between Asturleonese and Castilian, or Fala another language spoken in Extremadura which is most similar to Galician-Portuguese.
- Debuccalization (reduction to [h]) of [s] and [θ] in syllable-final position, as is common in Spanish varieties in the southern half of Spain.
- Frequent loss of d, in any position, as is common in Spanish varieties in the southern half of Spain.
- Simplification of the consonantic group -nf, to f
- Simplification of the consonantic group -rj, to j
- Simplification of the consonantic group rn, to nn
- Pronunciation of word-initial 'h' as a glottal fricative, [h], in many words in which Latin had an initial 'f', as is common in most Andalusian varieties.
- Occasional consonantic change l/r and r/l, which occurs in Andalusian Spanish as well
- General loss of r in final position