The vowel [o] could be short or long in Ilkorin. Non-final [o] generally survived from Primitive Elvish, except where it underwent i-affection. Short [o] could also develop from primitive [u] before final [a]. Long [ō] developed from primitive [ǭ] and [ā] (PE19/25; PE18/96). It is possible that the long [ō] in Ilkorin was actually pronounced as rounded [ǭ], as was the case for later North Sindarin (PE17/108).