Spanish Alveolar Trill and Alveolar Flap

The Spanish alveolar trill and alveolar flap contrast phoemically when they occur intervocalically. The contrast is exemplified in caro (expensive) and carro (car). In other positions, however, the two sounds are in complementary distribution.

Only the trill can occur word-initially and after /l/, /n/ and /s/. Examples include rey (king), alrededor (around), enredo (plot) and desregulación (deregulation). After a plosive or fricative other than /s/, only the flap can occur such as in tren (train) and frio (cold). In word-final position, the flap is more common but the trill can also occur, especially for emphasis.

The alveolar flap can be considered underlying. It occurs after plosives, after fricatives other than /s/, intervocalically and word-finally. The trill also occurs intervocalically, and after /s/ and the sonorants /l. and /n/. The alveolar tap has wider distribution. In word-initial position as well as after the fricative /s/ and the sonorants /l/ and /n/, the trill is the result of the process of fortition.

Spanish has two rhotic sounds, the trill and the flap. Since they can both occur intervocalically, they are classified as phonemes. Elsewhere, however, they are in complementary distribution. The alveolar flap has wider distribution and is thus considered the rhotic from which the trill was derived.