Which of the following sentences contain an infinitive and not an infinitive phrase?

1. Josh likes to sing in his car.

2. Kelsey turned her car to the left.

3. To fail in any activity is better than not to try at all.

4. The plan is to bake twelve dozen cookies.

5. all of these

6. none of these

1. infinitive phrase

2. not an infinitive phrase

3. infinitive phrase

4. infinitive phrase

5. false

6. false

Explanation:

An infinitive phrase is made up of "to" + "verb".

Not all the sentences contain infinitive phrases. Only 1, 3 and 4 contain infinitive phrases - sentence 2 does not have any infinitive phrase.

Let's analyze each of them!

1. Josh likes to sing in his car.

"to sing" is an infinitive phrase, because it introduces a verb and it expresses an action.

2. Kelsey turned her car to the left.

"to" is a simple preposition her and it does not introduce any verb, so it does not form an infinitive.

3 + 4

To fail in any activity is better than not to try at all.

The plan is to bake twelve dozen cookies.

Both sentences contain the infinitive phrases in bold, because the preposition "to" introduces a verb.