discern

behold, catch, descry, distinguish, espy, eye, look (at), note, notice, observe, perceive, regard, remark, see, sight, spot, spy, view, witness

difference, differentiate, discriminate, distinguish, secern, separate

appreciate, apprehend, assimilate, behold, catch, catch on (to), cognize, compass, comprehend, conceive, cotton (to or on to), decipher, decode, dig, get, grasp, grok, intuit, know, make, make out, perceive, recognize, register, savvy, see, seize, sense, tumble (to), twig, understand