Proto-Baltic: *es- (*es-meî), ptc. *sañt-
Meaning: be
Old Lithuanian: esmì (lit. esù, dial. esmù), esì, ẽst(i); ptc. santį, gerund. sant (später ē̆są̃s, ẽsant)
Lettish: ęsmu, gerund. ęsuot
Old Prussian: asmai, ast; 2 pl. opt. seīti, ptc. prs. sins, dat. sg. sentismu