What's the difference between consonance and assonance? Can someone point out a metaphor in Stephen Crane's poem? It is first block English class at Cambridge Rindge and Latin High School (CRLHS) as about 20 juniors try to get psyched about English literature perhaps only minutes after rolling out of bed.

In the front of the classroom, "Mr. Arribas" discusses today's poem with enthusiasm, urging the students to analyze and personalize Crane's use of figurative language. Soon, even the sleepiest students are volunteering to read aloud and to offer their own interpretations. By day, "Mr. Arribas" commands the respect and attention of these teenagers. By night, he doubles as Lucas Arribas Layton'00, an English concentrator living in Adams House.

Each weekday morning since early September, Layton has arisen before 7 a.m. He spends these days student teaching freshman and junior English classes at CRLHS. He then returns to Harvard to take classes from 4 to 6 p.m.

Layton's friends, accustomed to seeing him in running shorts, would hardly recognize him in his grown-up attire. Each morning, he dons a tie and dress coat, walks briskly to the high school and, voila!, quickly transforms from Luke to Mr. Arribas with super-man celerity. It's not just the clothes--his whole attitude seems to change.

During the day, in between the classes that Layton officially teaches, he observes his mentor-teacher, prepares lesson plans and meets with students.

Layton is one of only eight students currently teaching in Boston-area high schools and middle schools as the culmination of Harvard's Undergraduate Teacher Education Program (UTEP). Layton will graduate in June with a degree in English as well as certification to teach secondary school English in public schools.

The requirements of the program are few; students must take one half course in psychology, two half courses in educational methodology, an observation semester and complete 12 weeks of student teaching. But few Harvard students opt to participate.

According to UTEP Director Lissa Hodder, the Harvard undergraduates currently student teaching--in schools ranging from Martin Luther King Open Middle School to Watertown High School--handle their dual roles of student and teacher with ease. They write theses, apply for fellowships and manage the normal senior year stress.