In two recent studies I have attempted to show (a) how such ubiquitous grammatical categories as gender, number, case, person, and the parts of speech are interrelated and have given rise to new categories by mutual superimposition; (b) that the aspects of the Indo-European verb go back to three older verb classes, namely (I) verbs which express a physical or mental state like sleep, thrive, hate, (II) verbs designating a transition from one state into another: awaken, die, and (III) verbs indicating an action proper, i.e., an action caused by the volition of the subject: run, seize, give. It is the purpose of this paper to form a connecting link between these studies by showing that the three original IE verb classes are inextricably bound up with the category of voice or diathesis, which in turn has its origin in the distinction of the nominal and verbal phrase.

[The Hittite medio-passive shows a bewildering array of equivalent forms, but these are composed of relatively few formative elements. Aside from a few personal and modal endings, most of which appear in the active voice also, there are the medio-passive suffixes ti, t, ri, ni, ta, and a. All of these show affinities with the noun-system; the several medio-passive forms developed out of infinitives and participles, and they were gradually worked into new systems under the influence of the previously developed active verb.]

[1. Sp. bazo ‘yellowish brown’: βaϑὐ ‘deep-colored’. 2. Sp. cerdo ‘hog’: *seritare (severe) ‘sow, beget, produce’. 3. Sp. empachar ‘impede’ < *impattiare : *patta ‘paw’. 4. Sp. esquejar ‘make cuttings’ < *schistiare : schistos ‘fissile’. 5. Sp. estropear ‘cripple’ < *exturpidiare. 6. Sp. estrujar ‘squeeze out’ < *extrusulare : *extrusare ‘thrust out.’ ]

[The unaccented hombre as indefinite subject virtually faded out of use in Spanish in the sixteenth century, because of the competition of the passive, the impersonal reflexive, and other substitutes; because of its phonetic identity with the accented definite hombre ‘man’; possibly also because of the unwieldiness of an unaccented dissyllable.]

[1. MWelsh bel, Welsh rhy-fel ‘war’ are not borrowed from Lat. bellum, but are derived from IE *gwel- ‘prick’. 2. Welsh blew, Bret, bleo ‘hair’ are derived from *mleus, extension of IE *mel- in Grk. μαλλός, etc. 3. Ir. brat ‘mantle’, Welsh brethyn ‘cloth’, etc. are derivatives of IE *bher- in Grk. . 4. Welsh cyw ‘chicken, young of animals’ < *kuw- : Grk. , etc. 5. Welsh etifedd ‘heir’ belongs to tyfu ‘grow’. 6. Welsh llafrog, Bret, lavrek ‘breeches’ are from IE *(s)lb- ‘slack, loose’. 7. Ir. re(i)the ‘ram’ is a derivative of the root of Ir. rethim ‘run’. 8. MIr. sáilim ‘expect’, NIr. saoilim ‘think’ are cognate with ON seilask ‘seek for’, ChSl. sila ‘strength’, etc. 9. Welsh traul ‘wear, expense’ is derived from IE *terā-: *ter- ‘rub‘.]