This paper presents a fresh look at the etymology of the Slavic verb *jazditi ‘ride’ and discusses implications for the rise of the category of determinacy-indeterminacy in the verbs of motion in Slavic which follow from non-mainstream view of the etymology of this verb. The authors claim that the verb stem was formed as a serial verb containing both the inherited Indo-European elements ‘travel’ and ‘sit’. The formation suggests that the category of verbs traditionally labeled »indeterminate« are in fact manner of motion verbs.