Final answer:
An infinitive is a verb form that functions as a noun, adjective, or adverb. Three of the sentences contain an infinitive, while two do not.
Step-by-step explanation:
An infinitive is a verb form that functions as a noun, adjective, or adverb and is usually formed by adding 'to' before the base form of the verb. In the given sentences, the infinitives are:
- Kaya sent an e-mail to me. - Infinitive: to send
- Jess will go to the park. - No Infinitive
- I hope to hike tomorrow. - Infinitive: to hike
- I enjoy running and biking. - No Infinitive
- To worry is natural. - Infinitive: to worry
So, according to the sentences given, there are 3 sentences that contain an infinitive and 2 sentences that do not contain an infinitive.
Learn more about Identifying infinitives