It is suggested that the voicing process of Verner's Law did not follow the Germanic shift of IE /p t k kw s/, but was part of it. The shift itself was a form of secondary split, the allophones that were formed with less effort becoming respectively /
ð g gw z/ and those that were formed with more effort producing /f þ x xw s/: hence IE ∗dek'- > ∗teg.- > OE -tig 'decade, -ty', beside IE ∗dék- > ∗tex- > OS tehan ‘ten’. Except in initial position, the conditioning factor was the pre-Germanic primary accent. In initial position, the fixation of primary stress inhibited voicing by introducing or preserving more effort: IE ∗pḷnós > Go. fulls ‘full’. If the accent of IE ∗pḷnós had remained unchanged for centuries in Germanic, the Gothic would have been ∗bulls. Voicing was also inhibited in voiceless consonant clusters: ∗okt
ow > Go. ahtau ‘eight’. Unlike initial syllables, which were word-bound and received primary stress, a proclitic was phrase-bound and never fully accented: thus IE ∗kom'- > ∗gan'- > ∗ga'- > OE ge'-. The voicing process was not completely uniform in Germanic because the fixation of primary stress did not occur simultaneously in all words of all dialects. The frequent absence of medial voicing in Gothic is due to an earlier fixation of initial stress and to the very early separation of Gothic from the other Germanic dialects.