In many Philippine, northern Sulawesi, and northern Bornean languages, Proto Austronesian *kita 'first-person inclusive plural' became a first-person inclusive dual pronoun. Robert Blust and Hsiu-chuan Liao attribute this semantic change to drift (a change happening in various related languages independently). However, Lawrence Reid contends that it had already happened in Proto Malayo-Polynesian, and that the ensuing gap in the pronominal system of this ancestral language had been filled by the formation of a new first-person inclusive plural pronoun, which was based on *kita combined with a pronominal clitic (or "extender") *=mu. The latter was a second-person plural pronoun in Proto Austronesian, but after it had lost its plural meaning in Proto Malayo-Polynesian, it was often combined with or replaced by other pronominal extenders.
In this squib I show that in East Barito languages (including Malagasy) the first-person inclusive plural pronoun also derives from a dual *kita with a second-person plural extender. Taken in conjunction with the fact that reflexes of *kita also have a dual meaning in various languages in northern Borneo, this suggests that *kita already had a dual meaning in the early history of the West Indonesian subgroup.