Abstract
As the desiderative, -itasi first appears as a colloquial expression. This paper proposes a scenario of how the adjective itasi became a desiderative, taking over from the earlier -amaFosi, based on a distinction between post-verbal POSI and ITASI observed in a number of Ryukyuan dialects. In the Hatoma dialect (Southern Ryukyuan), -pus- (POSI) is the desiderative form, but -cca- (ITASI) is also attested, used predominantly when denoting involuntary physical actions. A similar situation is found in the Northern Ryukyuan dialect of Tsuha. In the Agarisuji dialect (Southern Ryukyuan), both POSI and ITASI can be used with the same verbs but the -cca- (ITASI) form implies a very strong form of desire, bordering on necessity. Necessity is what ITASI with involuntary actions indicates, so it can be seen that the Agarisuji situation is a development of the situation observed in the other dialects, with ITASI now co-occurring with controllable actions. It has been noted in the literature that, in contrast with -amaFosi, -itasi was commonly used with verbs expressing physiological desires. This is what would be expected if desiderative ITASI developed from the use of ITASI with involuntary physiological processes, meaning 'extreme feeling / necessity'. I propose that the desiderative usage of ITASI developed from a much earlier usage of ITASI with verbs denoting involuntary physical actions, meaning 'need to'. This is attested in the form nebu-tasi 'be sleepy', but it would also have been widely used in reference to other actions like going to the toilet or vomiting. Because the semantic change from 'sore' to 'physical necessity' appears to be rare (although a similar change is attested in the Yuman language of Hualapai), it is proposed that ITASI already had this meaning in Proto Japano-Ryukyuan, and that the development from 'physical necessity' to desiderative took place independently in mainland Japanese and the Ryukyuan dialects where ITASI is the general desiderative.
