Which sentence contains an infinitive?
1. Clayton asked his mother if he could take the bus to the skate park.
2. Although she was busy, Clayton's mother offered to give him a ride.
3. After sending an email to her boss, Clayton's mother grabbed her keys.
4. When Clayton got to his mother's car, he noticed she had a flat tire.
The sentence that contains an infinitive is 2. Although she was busy, Clayton's mother offered to give him a ride.
An infinitive phrase contains a verb in its infinitive form after the preposition "to". In this case, the infinitive phrase is "to give".
Even though the sentences in the other options contain the preposition "to", the preposition is not followed by a verb in its infinitive form. The preposition "to" is followed by noun phrases like "the skate park", "her boss" and "his mother's car".
