Eldamo : Ilkorin/Doriathrin : medial voiceless stops, nasals and [ɣ] became [s] before [s]

Ilk. medial voiceless stops, nasals and [ɣ] became [s] before [s]; [{ptknŋɣ}s] > [ss]

Ilk. medial voiceless stops, nasals and [ɣ] became [s] before [s]; [{ptknŋɣ}s] > [ss]

For voiceless stops, this rule can be deduced from examples in The Etymologies: ᴹ✶tupsē > Ilk. tuss (Ety/TUP), ᴹ✶taksē > Ilk. tass (Ety/TAK) and ᴹ√NAT > [natsē >] Dor. nass (Ety/NAT), the last example implied by its cognate ᴹQ. natse. For the nasals and [ɣ], the rule is described in Tolkien’s late notes on the development of Beleriandic [Ilkorin] ʒ and ñ, where he stated that “medial ñs > ns > ss; ʒs > ss” (PE18/104), though there are no attested examples of these changes. The development of [ms] is unclear, but it may have become [ss] as well.

[ls] became [ll] in contrast to the rule that medial voiceless stops, nasals and [ɣ] became [s] before [s]

Phonetic Rule Elements

[ps]	>	[ss]
[ts]	>	[ss]
[ks]	>	[ss]
[ns]	>	[ss]
[ŋs]	>	[ss]
[ɣs]	>	[ss]

Phonetic Rule Examples

takse > tasse	ks > ss	ᴹ✶taksē > Ilk. tass	✧ Ety/TAK
apsa > assa	ps > ss	ᴹ√AP > Ilk. ass	✧ Ety/AP
tupse > tusse	ps > ss	ᴹ✶tupsē > Ilk. tuss	✧ Ety/TUP
natse > nasse	ts > ss	ᴹ√NAT > Dor. nass	✧ Ety/NAT