Joel Rini
Galician dis, di, din of dicir are synchronically irregular because they lack a root-final consonant, i. e., di- vs. dig-, dic-. They are also diachronically irregular: Old Galician exhibited dizes, dize, dizen, but unlike Portuguese, Mirandese, Asturian, Castilian, and Aragonese, did not retain a root-final consonant. Considering the general retention of Ibero-Romance root-final consonants descendent from Lat. dῑc-, an explanation for the change of Old Gal. dizes, dize ~diz, dizen to Modern Gal. dis, di, din is in order.
Only two previous proposals have been put forth to date: 1) analogy with dá of dar; and 2) a so-called 3rd sg. -s “insólita” resulting from Old Gal. diz > dis. The former is deemed here untenable on theoretical grounds; the latter, though more plausible, is not unassailable given the maintenance of a 3rd singular final consonant normally associated with the 2nd person in closely related Portuguese and Mirandese. The present study therefore does not take as its point of departure 3rd sg. dis, but instead, a well-established process of historical morphology of the Ibero-Romance verbal system and two other irregular 3rd sg. forms, fai and vai of facer and ir, which point to a more likely explanation, namely syncretism.