Armenian has developed a set of prothetic vowels in its phonological history. One source of such prothetic vowels is through the interaction of historical epenthesis and metathesis of initial Cr-clusters: *Cr > *CVr > VCr.

The interaction between epenthesis, metathesis and subsequent vowel deletion also accounts for the emergence of root-internal/final VrC sequences from historical *VCr clusters: *VCr > *VCer > *VerC > VrC. On the surface, the change appears to be between consonants.

In addition, Picard (1989) also entertains a simpler analysis where the *VCr > VrC change is due to a single-step metathesis process, unrelated to the vowel epenthesis and deletion change in Armenian elsewhere.