"to be persistent" is the subject.
subject
The infinitive phrase plays the role of an adverb in this sentence. It tells why you met at the park. In the sentence "You met at the park to run", "to run" is the infinitive phrase.
"to finish your test" is the infinitive phrase.
Lisa wants to go quickly.
"You" is the subject. What did you do? you met. "Met" is the verb. "at the park" is a prepositional phrase (where did you meet?). You met to do what? You met to run. So "to run" becomes the direct object of the sentence.
"to be persistent" is the subject.
subject
The infinitive phrase "to be persistent" serves as the subject complement in the sentence, renaming or describing the subject "sign." It provides more information about the subject and completes the meaning of the sentence by expressing a quality or characteristic.
The infinitive phrase plays the role of an adverb in this sentence. It tells why you met at the park. In the sentence "You met at the park to run", "to run" is the infinitive phrase.
The infinitive phrase is "to join the circus" (an adverbial phrase).
"to finish your test" is the infinitive phrase.
Lisa wants to go quickly.
An infinitive phrase will start with the base form of a verb (e.g., to eat, to run) and function as a noun, adjective, or adverb. A prepositional phrase will begin with a preposition (e.g., in, on, at) followed by a noun or pronoun, and it functions as an adjective or adverb to describe a noun or verb.
"You" is the subject. What did you do? you met. "Met" is the verb. "at the park" is a prepositional phrase (where did you meet?). You met to do what? You met to run. So "to run" becomes the direct object of the sentence.
(to finish)
noun, adjective, and adverb
To help you