Gothic waurkeiþ. The opposite occurred regarding satjiþ, where the etymological *-iji-/*-ī- (PIE ) was decremented to *-i- because the light syllable created the environment for a light suffix. So, a Proto-Germanic *satijiþi was turned to *satjiþi by Sievers's reversal, which in turn was simplified prehistorically to *satiþi. Gothic re-inserts the -j- via analogy, yielding satjiþ (contrast Old English bideð, which does not re-insert the -j- therefore not yielding **biddeð). Hence, not only are Proto-Indo-European structures not needed to account for the facts of Germanic, they actually get in the way. Donald Ringe, in his book "From Proto-Indo-European to Proto-Germanic", characterizes the origins of the different features as follows: Sievers's law operates as a "surface filter"; therefore the objection concerning PIE vs. Proto-Germanic *wurkīþi is not valid. That is, Sievers's law was not a sound change that took place at some particular time, but rather a phonological law that remained in the grammar of the language over time and operated on the output of various phonological processes. When PIE changed to *ur in Proto-Germanic, Sievers's law automatically changed forms such as to . The converse of Sievers's law – which changes to after a light syllable – was indeed a Germanic innovation that did not apply to PIE. Essentially, Proto-Germanic inherited Sievers's law from PIE and then extended it to apply in both directions. This answers the concern about *satiþi vs. . The extension of the Sievers's-law variant to polysyllabic as well as heavy-syllable stems was another Germanic innovation. Sievers's law in Germanic was clearly conditioned on morphological grounds as well as phonological, since suffixes were treated as separate words if they were recognised as separate morphological segments. For example, the suffix *-atjaną had a nonsyllabic -j- because the preceding -at- was light, as in Old English -ettan, where the gemination is evidence for -j-. On the other hand, *-ārijaz had -ij- because the syllable -ār- was heavy, as in Gothic -areis, which would have been *-arjis if the suffix had contained -j- instead. This happened even though in fully formed words these -j- and -ij- would have been preceded by two syllables. Examples of the opposite - that is, multiple-syllable stems that were not segmentable - can also be found. *hamiþiją ("shirt") clearly contained -ij-, showing that *hamiþ- in its entirety was analysed as the stem, rather than just *-iþ- since there was no such suffix in Proto-Germanic. This is