Answer: B) i’m working to save up for some new music, D) denise likes to get her exercise by dancing, and E) dave has to walk the dog every morning.
Explanation: An infinitive is the basic form of a verb, without an inflection binding it to a particular subject or tense. It is preceded by a particle “to,” and can serve as an adjective, an adverb, or a noun. From the given options, the ones that contain an example of infinitives are the options B, D, and E, because they have the particle "to" followed by a verb. In options A and C, the word "to" acts like a preposition and it isn't followed by a verb.
The infinitive is the base form of a verb that has no inflection binding it to a particular subject or tense. Some examples are <em>to think, to be, to see</em>. The infinitive verbs of the sentences are in bold:
2. I'm working <u>to save up</u> for some new music.
4. Denise likes <u>to get</u> her exercise by dancing
5. Dave has <u>to walk </u>the dog every morning.
Sentences number 1 and 3 do not contain an infinitive. The use of the preposition "to" here expresses motion or direction toward a point, person, place, or thing.