Omega-verbs
The -mi verbs are a class of athematic verbs in the Proto-Indo-European language. The name derives from the first-person singular form of the verbs in the present indicative active. The person marker is -mi, e.g. εἰμί (eimí, I am), δίδωμι (dídōmi, I give), φημί (phēmí, I say) etc. The conjugation of mi-verbs differs from the conjugation of the much more common, thematic, omega-verbs (-ω, -ō).