Yes, the sentence "Alex will be taken out for ice cream by his parents to celebrate his hard work" is in the passive voice. In this sentence, the subject (Alex) is the receiver of the action, and the doer of the action (his parents) comes after the preposition "by."
To convert it to active voice, you could say: "His parents will take Alex out for ice cream to celebrate his hard work." In this version, the subject (his parents) performs the action.
1 answer