The origin of the extension *-tū is not entirely certain. It may go back to the PS pronominal marker of the oblique case (see Akk.
šuāti, Ug.
hwt, Sab.
hwt). However, it seems more probable to interpret it as the deictic element attested in other EthS pronominal forms (see, for example, Geez
zəntu). See Bulakh–Kogan 2013b:97.