A special geminate like ff in maffa ‘pillow’, which does not exist in Standard Japanese (SJ) is found in the Antoh dialect in Fukui Prefecture. This paper deals with the synchronic and diachronic phenomena concerning the ff geminate in addition to bb and ss. This paper has the following purposes:
(1) to illustrate the correspondence of geminates between the Antoh dialect and SJ,
(2) to investigate the historical development of the geminates in the Antoh dialect,
(3) to point out that the manifestation of the geminates in the Antoh dialect is similar to that of the Miyako-jima dialect in the Ryukyuan language, and
(4) to propose that the explanation for the processes of the geminate in this dialect gives a suggestive source to the discussion on the processes of sound changes in the Ryukyuan language.