In the sentence "She plays the piano beautifully," what part of speech is "beautifully"?

In the sentence "She plays the piano beautifully," "beautifully" functions as an adverb. An adverb modifies verbs, adjectives, or other adverbs, providing more information about how an action is performed. In this case, "beautifully" describes how she plays the piano, indicating the manner of the action.

Words classified as adjectives, on the other hand, serve to modify nouns and pronouns, providing descriptive qualities, but "beautifully" does not fit that role in this context. Similarly, nouns identify people, places, things, or concepts, while prepositions show relationships between their objects and other parts of the sentence but are not applicable in this scenario. The role of "beautifully" as an adverb makes it the correct part of speech in this sentence, enhancing the understanding of her piano-playing skills.