Answer:
. To form the past participle of regular verbs, we usually add -é for -er verbs, -i for -ir verbs, and -u for -re verbs. For example:
parler (to speak) → parlé (spoken)
finir (to finish) → fini (finished)
vendre (to sell) → vendu (sold)
To put these sentences in the passé composé, we need to conjugate the auxiliary verb avoir according to the subject, and then add the past participle of the main verb. For example:
1- I grilled a hamburger
Je (I) → j’ai (I have)
griller (to grill) → grillé (grilled)
J’ai grillé un hamburger.
2- You went camping in the trees
Tu (you singular informal) → tu as (you have)
aller (to go) → allé (gone)
Tu es allé camper dans les arbres.
Note: Aller is an irregular verb that uses être as the auxiliary verb instead of avoir. Also, the past participle agrees with the subject in gender and number when using être. In this case, we add an -e to allé if the subject is feminine, and an -s if the subject is plural.
3- We sunbathed at the pool
Nous (we) → nous avons (we have)
se bronzer (to sunbathe) → se bronzé (sunbathed)
Nous nous sommes bronzés à la piscine.
Note: Se bronzer is a reflexive verb that also uses être as the auxiliary verb. The reflexive pronoun agrees with the subject and comes before the auxiliary verb. The past participle also agrees with the subject in gender and number when using être. In this case, we add an -s to bronzé because the subject is plural.