a word that connects the subject to the complement and describes the subject

also called a linking verb

typically a verb of sensation or existence

act, appear, be, become, continue, feel, get, go, grow, keep, lie, look, own, prove, remain, resemble, run, seem, sit, smell, sound, stay, strand, taste, turn

act, appear, be, become, continue, grow, prove, remain, seem, sit, strand, turn

feel, look, smell, sound, taste