Spanish quepo: the untold story

The pres. ind. paradigm of Sp. ‘to fit’ exhibits a synchronically irregular form in the 1st pers. sg., i.e., , instead of a synchronically regular form derived from the infinitive, i.e., → * . However, is not considered at all historically irregular. Since the first historical grammar of Spanish, has been understood to be a direct continuation of Lat. , which apparently evolved through regular phonetic development, like pres. subj. > , > . Nonetheless, one may question why has not been replaced by * in Modern Spanish given its extremely low frequency of occurrence, as forms of a language that occur infrequently are often regularized. A historical look at reveals the following surprising facts: (1) Although pres. subj. is attested from the earliest Old Spanish texts onward, is absent from the written record throughout the Old and Medieval Spanish periods and does not appear until the end of the sixteenth century; (2) Regularized served as the first person singular of the present indicative until then. The present study attempts to explain through well-established processes of historical morphology the late appearance of and its continued existence in Modern Spanish.