If you are a teacher, you must read this book. If you are a par

ent, you may learn many useful things by reading it. If you are a student and read it, you will mourn that you never were lucky enough to have Frank McCourt for a teacher.

Frank McCourt is the author of Angela's Ashes and 'Tis. Teacher Man is the third book of his memoirs, and the lightest and funniest. Perhaps you cried over Angela's Ashes; you will laugh with Teacher Man.

McCourt says in the Prologue, "When I taught in New York City high schools for 30 years no one but my students paid me a scrap of attention. In the world outside the school I was invisible. Then I wrote a book about my childhood and became mick of the moment."

He was 66 when Angela's Ashes was published. When asked what took him so long, he replies that teaching five high school classes a day, five days a week, occupies the mind fully.

He presents himself as a fearful, insecure man, daring to face New York City teenagers. The fact that he spent 30 years doing just that makes one wonder how fearful he really was. Certainly he was brave and inventive. One of the first anecdotes he relates is about his first day on the job, when he handles a disruptive classroom by eating the sandwich that someone throws. "It was not any ordinary sandwich where meat is slapped between slices of tasteless white American bread. This bread was dark and thick . . . drizzled with olive oil and charged with a tongue-dazzling relish. I ate the sandwich."

After two years in the army, he had attended college, though woefully unprepared for higher education. "I shuffled and mumbled the mishaps of my life to patient professors, hinted at great sadness. The Irish accent helped. I lived on the edge of faith and begorrah."

That accent and the stories of his horrendous childhood soon won over the tough guys and girls in his classes. Now he tells the stories of many of those students, and the reader is won, too. McCourt was clearly a very popular teacher, whose classroom was seldom orderly or disciplined. Yet his students learned, through his stories and his unusual pedagogical methods.

He not only told stories, he sang Irish folk songs, and he and his students studied the narrative strategies of recipes, nursery rhymes, and excuse notes (the latter usually written by students trying to sound like their parents).

His last teaching years were spent in high-powered Stuyvesant High School, teaching creative writing. Finally he decided that he shouldn't be telling others how to write when he wasn't doing it himself. As he leaves on his last day, "Someone calls, Hey, Mr. McCourt, you should write a book."

So he did. It's available at the Mary Willis Library.