Convert the sentence "La chorale chantera les hymnes" from active to passive voice.

Step 1: Analyze Question 20.
The sentence "La chorale chantera les hymnes" is in the active voice, future simple tense. To convert it to the passive voice, we use the structure: direct object + auxiliary verb "être" in the same tense as the active verb + past participle + "par" + subject.
"Les hymnes" (masculine plural) is the direct object.
"chantera" (future simple of chanter). The future simple of "être" for "ils/elles" is "seront".
The past participle of "chanter" is "chanté". It must agree with "les hymnes", so it becomes "chantés".
Thus, the passive form is "Les hymnes seront chantés