Verbs beginning with a simple consonant (except ρ) or with a stop and a liquid (λ, μ, ν, ρ) place the initial consonant with ε before the stem. λύ_ω
a. Exceptions: verbs beginning with γν, most of those with γλ, and some with βλ. Thus, γνωρίζω
Herbert Weir Smyth [n.d.], A Greek Grammar for Colleges; Machine readable text [info] [word count] [Smyth].