How does the Basque r sound differ from the Basque rr sound?

In the Basque language, the distinction between the two types of r sounds is based on the manner of articulation:

• The r sound: This is produced by a single tap of the tongue against the roof of the mouth. This sound is technically classified as a tap, where the tongue tip makes a brief, single contact with the alveolar ridge or the roof of the mouth.12
• The rr sound: This is a rolled or trilled sound. Unlike the single tap, this involves a series of rapid vibrations of the tongue against the roof of the mouth.13

This contrast is similar to the phonological distinction found in Spanish, where the difference between a tap and a trill is used to differentiate between words.12