S. [ɣ] became [i] between sonants and vowels; [{lrð}ɣV] > [{lrð}iV]

S. [ɣ] became [i] between sonants and vowels; [{lrð}ɣV] > [{lrð}iV]

Where [ɣ] appears between a sonant (voiced consonants like [l], [r] and [ð]) and a vowel, it changed into the vowel [i], as noted by David Salo (GS/§4.152). Probably it passed through [j] (“y”) in the process so that (for example) medial > ly > li. All the examples we have of this phonetic development are from Noldorin, but we have no reason to believe Sindarin was any different:

The last example was deleted, since it shows a sound change of [zg] > [ðɣ] that Tolkien was unsure of during the Noldorin period of the 1930s (he ultimately adopted this sound change for Sindarin in the 1960s). In terms of the development of [ɣ] > [i], however, it is consistent with the other examples, indicating that this sound change could occur after voiced consonants other than the liquids [l], [r].

There are a few cases, however, where this sound change did not occur:

These examples indicate that before high vowels like [u], [y] (and probably also [i]) the [ɣ] simply vanished instead.

Conceptual Developments: As discussed by Roman Rausch in his Historical Phonology of Goldogrin (HPG/§2.6) and Historical Phonologies of Ilkorin, Telerin and Noldorin around 1923 (HPITN/§4.1.4), there are hints of similar sound changes in the Gnomish of the 1910s and the Early Noldorin of the 1920s:

Order (02800)

After 00500 voiced stops became spirants after liquids ON. Dirghel > N. Diriel
ᴹ✶stalgondō > N. thalion
Ety/DER
Ety/STÁLAG
Before 03100 [ɣ] otherwise vanished ᴹ✶stalgondō > N. thalion Ety/STÁLAG

Phonetic Rule Elements

[lɣV] > [liV]
[rɣV] > [riV]

N. [ɣ] became [i] between sonants and vowels; [{lr}ɣV] > [{lr}iV]

GS/§4.152 @@@

Order (02700)

After 00600 voiced stops became spirants after liquids ON. Dirghel > N. Diriel
ᴹ✶stalgondō > N. thalion
Ety/DER
Ety/STÁLAG
Before 03000 [ɣ] otherwise vanished ᴹ✶stalgondō > N. thalion Ety/STÁLAG

Phonetic Rule Elements

[lɣV] > [liV]
[rɣV] > [riV]
[ðɣV] > [ðiV]
[lɣi] > [li]
[lɣy] > [ly]
[lɣu] > [lu]

Phonetic Rule Examples

θalɣond > θaliond lɣV > liV ᴹ✶stalgondō > N. thalion ✧ Ety/STÁLAG
ulɣund > ulund lɣu > lu ᴹ✶ulgundō > ulund > N. ulun ✧ Ety/ÚLUG
θelɣyndi > θelyndi lɣy > ly ᴹ✶stalgondō > N. thelyn ✧ Ety/STÁLAG
dirɣel > diriel rɣV > riV ON. Dirghel > N. Diriel ✧ Ety/DER
tarɣass > tariass rɣV > riV ᴹ√TÁRAG > N. tarias ✧ Ety/TÁRAG
maðɣass > maðiass ðɣV > ðiV ᴹ√MÁSAG > N. maðias ✧ EtyAC/MASAG