How do I know when to use the verb 'etre' or 'avoir' in the past tense? (how do I form the simple past tense?)

First of all, lets revise the verbs etre and avoir etreJe suisTu esIl/elle estNous sommes Vous êtes Ils/elles sont avoirj'ai tu as il/elle anous avons vous avezils/elles ont The past tense needs 3 parts, the subject (the person doing the action) the verb auxiliary verb 'avoir' or 'etre' (conjugated) and the past participle. e.g:IL (subject) A (auxiliary 'avoir') MANGÉ (past participle of verb)As a general rule, assume all verbs take 'avoir' EXCEPT... the DR&MRS DAVENTRAMP verbs! Devenir (to become) Revenir (to come back) Monter (to go up)Rentrer (to go home/return)Sortir (to leave/go out) Descendre (to go down) Aller (to go) Venir (to come) Entrer (to enter)Naitre (to be born) Tomber (to fall) Rester (to stay)Arriver (to arrive) Mourir (to die) Partir (to leave)The past participle comes after the auxiliary verb. Regular verbs take the infinitive stem with a changed ending: -er => é-re => u -ir => i HOWEVER... When we use the DR MRS DAVENTRAMP verbs with 'etre' in the past, the past participle must agree with the subject. That means that feminine subjects add an extra e and plural subjects add an extra se.g IL EST ALLÉELLE EST ALLÉEILS SONT ALLÉSELLES SONT ALLÉES