Finite Verb in Sentence A: I like to swim.

The sentence "I like to swim" contains a finite verb. Let's break it down to understand why.

Subject: The subject of the sentence is "I", which is the first-person singular pronoun.

Verb: The main verb in the sentence is "like." It expresses the action or state of the subject.

Object: The object in the sentence is "to swim." It functions as the direct object of the verb "like" and represents the action that is liked by the subject.

Now, let's analyze the other options to see why they do not contain finite verbs:

Sentence B: Swimming is fun.

- Subject: The subject is "swimming," which is a gerund. Gerunds are verb forms that function as nouns.
- Verb: There is no finite verb in this sentence. The word "is" is a linking verb and does not express an action or state.
- Object: There is no direct object in this sentence.

Sentence C: Having swum, I felt refreshed.

- Subject: The subject is "I," the first-person singular pronoun.
- Verb: The word "having swum" is a participial phrase. Participles are verb forms that can function as adjectives or parts of verb phrases. However, in this sentence, the participle "having swum" is not a finite verb.
- Object: There is no direct object in this sentence.

Sentence D: To swim is my favorite hobby.

- Subject: The subject is "to swim," which is an infinitive phrase. Infinitives are verb forms that are typically preceded by the word "to" and can function as nouns, adjectives, or adverbs. In this sentence, the infinitive "to swim" is acting as a noun.
- Verb: There is no finite verb in this sentence. The word "is" is a linking verb and does not express an action or state.
- Object: There is no direct object in this sentence.

Therefore, the sentence that contains a finite verb is option A: "I like to swim."