LINKING VERB

Also called a copula or connecting verb, it is a verb, such as be verbs (am, is, are, was, were, be, been, being) and intransitive verbs (appear, become, feel, grow, look, prove, remain, seem, smell, sound, stand, stay, turn, among others), that connects the subject of a sentence to its complement.

My twin sister is someone who is different from any normal person, or at least, from me.