Answer:
Infinitive phrase: To play the piano
Use: Noun and subject
Explanation:
Infinitives are a type of verbal that do not act as verbs in a sentence but as adjectives, adverbs or nouns. This verbal is formed with the word "to" + the simple present form of a verb. For example, To + play = To play. Infinitive phrases, then, has an infinitive that is followed by any objects, and/or modifiers.
In the sentence provided, "To play the piano" is an infinitive phrase because it consists of the infinitive "to play" and other words: "the piano". Besides, it is acting as a noun (It refers to the practice of playing the piano) and the subject of the sentence (It is what's being talked about).
