1) The author uses informal English when speaking with friends, family members, and children. She provides an example of using simple terms to explain the concept of step-parents to her young nephew.
2) She also uses informal English when texting with her sister, using puns and slang terms.
3) In contrast, the author uses formal English when speaking with strangers, professors, and older generations. She provides an example of using polite terms and clear language when calling AAA about locking her keys in her car.