What role does the infinitive phrase play in sentence to be persistent is a sign of stubbornness?

In the sentence "To be persistent is a sign of stubbornness," the infinitive phrase "to be persistent" functions as the subject of the sentence.

Here's why:

* Infinitive Phrases: An infinitive phrase is formed by the word "to" followed by a verb (e.g., "to be," "to run," "to eat"). They can act as different parts of speech within a sentence.

* Subject: The subject of a sentence is the person, place, or thing that performs the action of the verb. In this case, the action is "is" (the verb), and the subject is "to be persistent" – the act of being persistent.

Therefore, the infinitive phrase "to be persistent" acts as the noun that performs the action of the verb "is."