Le Preterit et le Present Perfect :

I/ L’emploie des temps :
Preterit : évènement passé terminé et daté, n’ayant pas de conséquences au présent. →I bought a car in 2011. (J’ai acheté une voiture en 2011.)
Present Perfect : évènement terminé qui a eu lieu dans le passé et qui a des conséquences aujourd’hui (expérience) → I have bought a car. (J’ai acheté une voiture.)
Obligations:
Phrase affirmative: Never /Already → Present Perfect (I never/already visited Paris.)
Phrase interrogative : Ever → Present Perfect (Have you ever/already visited Paris?)
Phrase affirmative : Ago → Preterit (I visited Paris 2 years ago.)

II/ Construction :
Preterit : verbe au preterit (-ed) Verbe régulier → I cleaned Verbe irrégulier → I saw
Present Perfect : opérateur HAVE au présent + p.passé Verbe régulier → I have cleaned / She has cleaned Verbe irrégulier → I have seen / She has seen

III/ La forme interrogative:
Les opérateurs : Present : Do/ Does Preterit: Did Present Perfect : Have/ Has
Present: Do/ Does + sujet + verbe Ø +...? → Do you cut your hair ? / Does she cut her..?
Preterit: Did + sujet + verbe Ø +...? → Did you cut your hair ?
Present Perfect: Have/ Has + sujet + p.passé (-ed) +…? Verbe régulier → Have you brushed your hair? / Has she brushed her hair? Verbe irrégulier → Have you cut your hair? / Has she cut her hair?
Pour la forme négative: On rajoute la négation après l’opérateur.

IV/ Réponses brèves:
Present: Yes, I do / No, I don’t
Preterit: Yes, I did / No, I didn’t
Present Perfect: Yes, I have / No, I haven’t

V/ Examples:
Present: Do you eat sweets? → Yes, I do. / No, I don’t. I eat sweets. I don’t eat sweets.
Preterit: Did you eat sweets? → Yes, I did. / No, I didn’t. I ate sweets. I