The sentence "The girl recited the poem beautifully" is in the active voice. In this construction, the subject "the girl" performs the action of reciting, which is conveyed by the verb "recited." The focus of the sentence is on the subject and what she is doing, making it clear that she is the one actively engaging in the action, rather than being acted upon. To change this sentence to passive voice, I would write, "The poem was recited beautifully by the girl." In this revised sentence, the focus shifts to "the poem," which receives the action, while "the girl" becomes a passive agent introduced by the preposition "by."
Proofread for proper capitalization, punctuation, and grammar: The girl recited the poem beautifully. The poem was recited beautifully by the girl.