Q. virya- v. (ya-formative) “to change, alternate”
This verb is intransitive, so it can be used of change of self but not of others. For change of others, use vista-.
One form of this word, wirne (PE17/191), is unclear in function. It is glossed “change” and could be a noun. However, it almost identical in form to the strong-past virne of virya- attested on PE17/189. It seems likely to me that this is the archaic form of the strong-past tense from before the change of ✶w- to v-.
Evidence elsewhere suggests the noun form of “change” is vistë.
References ✧ PE17/189, 191
|virinye||past; half-strong-past||✧ PE17/189|
|virne||past; strong-past||✧ PE17/189|
|√WIS > virya-||[wisja-] > [wizja-] > [βizja-] > [vizja-] > [virja-]||✧ PE17/189|
|√WIS > virya||[wisja-] > [wizja-] > [βizja-] > [vizja-] > [virja-]||✧ PE17/191|