In this answer key for Exercise #2, the following answers are included:

   C    1. The one woman who did not attend the meeting said that she had to study for her chemistry exam. [who did not attend the meeting is an essential clause, defining the specific woman in question.]

   X    2. He did not however intend to return the money he borrowed. [however is a Non-Essential word.]

   X    3. West Point cadets, who break the honor code, are expelled. [who break the honor code is an essential clause, defining a subset of cadets.]

   X    4. She was as a matter of fact chiefly interested in becoming a Hollywood celebrity. [as a matter of fact is a Non-Essential phrase.]

   C    5. Raul's wife, Conchita, is president of the local Red Cross. [Conchita is a Non-Essential word since Raul's wife already defines the specific person in question.]

   X    6. The German writer, Hermann Hesse, is a favorite with American college students. [Hermann Hesse is an essential term, defining the specific German writer in question.]

   X    7. The courthouse which was renovated recently was built in 1878. [which was renovated recently is a Non-Essential clause since the courthouse already defines the specific building in question.]

   X    8. Saul having forgotten to save his work lost all of his revisions when his computer crashed. [having forgotten to save his work is a Non-Essential phrase, merely modifying the word Saul.]

   C    9. St. Ignatius of Loyola, founder of the Society of Jesus, wrote his handbook of spiritual exercises in the sixteenth century. [founder of the Society of Jesus is a Non-Essential phrase, merely providing additional information about the subject.]

   X    10. The book, that your sister gave you for your birthday, won a National Book Award. [that your sister gave you for your birthday is an essential clause, defining the specific book in question.]