Proterokinetic

The Proto-Indo-European word for ‘thought’ was proterokinetic: nominative singular *mén-ti-s, genitive *mn̥-téy-s.

Proterokinetic ('earlier-mobile'): the accent moves between the first syllable and the stem. As in the acrostatic type, ablauting endings were in zero grade. The type is clearly seen in the ablauting u-stem neuters and their analogs, as *doru 'tree, wood', gen. *drews (that is, *dór-u, *dr-éw-s); *nóm-n̥ 'name', gen. *n̥m-én-s; *gʷén-H₂- 'woman', gen. *gʷn-éH₂-s.

The other three polysyllabic types exhibited alternating accent: on the leftmost syllable of the stem in the direct cases and on the endings in the oblique cases ('amphikinetic' accent); on the rightmost syllable of the stem in the direct cases and on the endings in the oblique cases ('hysterokinetic' accent); or on the penultimate syllable of the stem in the direct cases and on the rightmost syllable of the stem in the oblique cases ('proterokinetic accent). Note that in every one of these patterns the accent was to the left in the direct cases and to the right in the oblique cases. [...] Proterokinetic inflection may have been the most widespread type among polysyllabic athematic nouns in late PIE. Whole classes of nouns followed this accent paradigm, including, for instance, feminine nouns in */-tey-/ (e.g. *dʰéh₁-ti- ~ *dʰh₁-téy- 'act of putting', *gʷém-ti- ~ *gʷm̥-téy- 'step, act of walking', *mén-ti- ~ *mn̥-téy- 'thought'), masculine nouns in */-tew-/ (e.g. *ǵéws-tu- ~ *ǵus-téw- 'taste'), most neuters in */-men-/ (e.g. *séh₁-mn̥ ~ *sh₁-mén- 'seed'), most feminines in *-h₂- that were not derived from o-stems (e.g. *gʷénh₂- - ~ *gʷnéh₂- 'woman', *h₁widʰéwh₂- ~ *h₁widʰwéh₂- 'widow'), and a large number of neuter r/n-stems (e.g. *péh₂wr̥ ~ *ph₂uén- 'fire'; cf. Schindler 1975a: 9-10).

In proterokinetic nouns, the root is in the full grade and accented in the strong cases, and both accent and full grade shift to the suffix in the weak cases. Most i- and u-stems (§6.42) in Sanskrit appear to have been proterokinetic