Voici : from Vois (Voir verb = to see) + ci (from Ceci = pronom démonstratif) Used to catch people attention on an object. example : "Voici ma soeur" (Here's my sister *pointing finger*) C'est : from Ce (Pronom démonstratif) + est (être verb) It is casual sentence structure (Pronom + verb) Used to describe a thing example : "C'est ma soeur" (this person is my sister) or "C'est beau" (this is beautiful) Hope it helps