Quenya Phonetics P15: [ɸ], [β] became [f], [v]

Q. [ɸ], [β] became [f], [v]; [ɸ|β] > [f|v]

In Quenya the bilabial spirants ꝑ, ƀ [ɸ, β] (as derived from primitive ph, b) both became labio-dental f, v. These sound changes were mentioned in both the Outline of Phonetic Development [OP1] from the 1930s and the Outline of Phonology [OP2] from the 1950s:

Quenya Phonetics P13: [ae], [ao] generally became [ē], [ō]

Q. [ae], [ao] generally became [ē], [ō]; [ae|ao|ā{ĕŏ}] > [ē|ō|ā]

Quenya did not tolerate the vowel combinations [ae] or [ao], and these generally became [ē] or [ō]. These sound changes explain the somewhat peculiar rule that the genitive form of nouns ending in -a was -o, for example:

Quenya Phonetics P12: [ɣ] from [g] vanished

Q. [ɣ] from [g] vanished; [ɣ] > [ø]

In Quenya when the voiced stop g became spirantal ʒ [ɣ], the resulting spirant generally vanished. This sound change is distinct from the much more ancient vanishing or ʒ (or h) in Primitive Elvish. Tolkien gave essentially the same description of this sound change in both the Outline of Phonetic Development [OP1] from the 1930s and the Outline of Phonology [OP2] from the 1950s, but with more details in OP2:

Quenya Phonetics P11: [w] became [β] initially and between vowels

Q. [w] became [β] initially and between vowels; [w-|VwV|aiw] > [β-|VβV|aiw]

In Quenya an initial or intervocalic w became v. The same basic phonetic developments were discussed in both the Outline of Phonetic Development [OP1] from the 1930s and the Outline of Phonology [OP2] from the 1950s, but the timing and details of the sound changes were not the same. In the 1930s [OP1], this was a fairly recent sound change, occurring in the Tarquesta (TQ) period and possible in Lindarin only [pre-Vanyarin]:

Quenya Phonetics P10: [wo] became [o]

Q. [wo] became [o]; [wo-] > [o-]

Starting in the 1930s, the combination wo sometimes reduced o, but the exact conditions under which this change occurred are unclear. Tolkien gave nearly identical descriptions of this sound change in both the Outline of Phonetic Development [OP1] from the 1930s and the Outline of Phonology [OP2] from the 1950s:

Quenya Phonetics P9: [lɣ], [rɣ] became [ll], [rr]

Q. [lɣ], [rɣ] became [ll], [rr]; [lɣ|rɣ|{lr}ɣw] > [ll|rr|{lr}w]

As described in the Outline of Phonology [OP2] from the 1950s, the combinations rg, lg became rr, ll by time of Tarquesta [TQ], probably passing through lʒ, rʒ [lɣ, rɣ] in the process. However, this sound change only occurred in the Ñoldorin dialect of Quenya:

Quenya Phonetics P8: spirants became stops after nasals

Q. spirants became stops after nasals; [mɸ|nθ|ŋx|nð] > [mp|nt|ŋk|nd]

In Quenya anytime a nasal came into contact with a voiceless spirant in the Parmaquesta [PQ] period, the spirant was restopped. Tolkien mentioned this development in both the Outline of Phonetic Development [OP1] from the 1930s and the Outline of Phonology [OP2] from the 1950s:

Quenya Phonetics P7: spirants became stops after [r], [l]

Q. spirants became stops after [r], [l]; [{rl}{ɸθxð}] > [{rl}{ptkd}]

After liquids r, l many spirants that arose from either aspirates or voiced stops once again became stops. Tolkien described these phonetic developments in several place in the Outline of Phonology [OP2] from the 1950s. For aspirates > voiceless spirants > voiceless stops after liquids: