Question

What are the differences between past tense using être vs avoir (French)

Please explain it simply and not to long with few differences (like 3 or 4)

Answer 1

if you mean the difference between passé composé auxiliaries than you use être when you're using a DR MRS VANDERTRAMP verb which is an acronym of all the verbs of movement (devenir, revenir, monter, rentrer, sortir, venir, aller, naître, descendre, entrer, retourner, arriver, rester, partir). we also use être if there is a reflexive pronoun (me te se nous vous se)