The Primitive Elvish a-fortified long vowels ę̄ and ǭ became ē and ō in the Quenya of the 1950s. Tolkien mentioned this development in both the second version the Tengwesta Qenderinwa (TQ2: PE18/96) and the Outline of Phonology (OP2) from the 1950s (PE19/106). The same developments held in the 1930s and 40s (TQ1: PE18/47; OP1: PE19/53), except in that period Tolkien represented a-fortified e as ǣ rather than ę̄. Examples of these sound changes are rare but can be found in both conceptual periods:

• √MEL > Q. méla vs. T. mála “loving” (VT39/10) [in Telerin, ę̄ > ā].
• Val. Arǭmēz > Arōmē > Q. Orome (WJ/400).
• ᴹ✶wǣdē > ᴹQ. vére “bond” (Ety/WED).
• ᴹ✶mǭri > ᴹQ. móre “blackness” (Ety/MOR).

As the Orome example illustrates, this must have been a somewhat ancient change, before unstressed medial long vowels shortened.

Conceptual Development: There is no evidence of anything like a-fortification in Tolkien’s earliest conception of Primitive Elvish in the 1910s and 1920s.