Length in strange places: Qualitative enhancement of sonorant quantity in Celtic and beyond

Present-day Celtic languages are characterized by a typologically relatively unusual contrast between ‘lenis’ and ‘fortis’ coronal sonorants. It is especially developed in the Gaelic languages. Here, ‘fortis’ nn ll rrcontrast with ‘lenis’ l n r in postvocalic position (Irish geal ‘bright’ vs. geall ‘promise’). Furthermore, they participate in the initial mutation system, where the ‘fortis’ sonorants generally occur in the unmutated (‘radical’) grade, and ‘lenis’ ones in the ‘lenited’ grade, which historically corresponds to postvocalic contexts. In the Brythonic languages, the most notable correspondent of this pattern is found in Welsh, where ll [ɬ] acts as the ‘fortis’ counterpart of [l]: they contrast postvocalically, and [ɬ] is generally the radical consonant in mutation.