"I love to study, I love to read and I love the classroom," Margaret Mary Casey told an interviewer a few years ago. She was 90 at the time and had been studying, reading and teaching for most of her long life.

Ms. Casey, 96, for many years an English teacher at Bethesda-Chevy Chase High School, died Aug. 12 at her home in Silver Spring. She had fibrotic lung disease.

She was born on Shakespeare's birthday, April 23, in Pawcatuck, Conn., the second of five children of Irish immigrants Patrick Francis Casey of Upper Tennis and Bridget Mary O'Leary of Glenerah. She grew up in a three-story home in Cumberland Hill, R.I., with aunts, uncles and cousins across the street and a magnificent orchard she always loved in the back yard.

As a youngster and as a teacher, her year always began in September. "As a child I could think of nothing more rewarding than a new dress, a new taffeta hair ribbon, a new pair of shoes, a new pencil box and a new grade," she wrote in a journal she kept for many years.

Ms. Casey was a 1930 graduate of Seton Hill College in Greensburg, Pa., where she was a Greek and Latin major and an English minor. She began her career as a fourth-grade teacher at Cumberland Hill Grammar School and then accepted a position in the English department of Cumberland Hill High School.

Teaching in the midst of the Depression, she once went for a year without pay, and, when she did get paid, she used the money to help her father make sure her brother and sister could attend college as well. She also was working at the time toward her master's degree in English, which she received from Rhode Island College of Education in 1935.

A lifelong traveler, Ms. Casey celebrated her new degree by taking a six-week cross-country bus trip. She camped out in tents, rode a donkey into the Grand Canyon and viewed Yosemite National Park.

In later years, she trekked across Europe, visited every significant literary and historical site in England and took trips to Egypt, India, Australia, New Zealand, Hong Kong and the Himalayas. She celebrated her 65th birthday by going on an African safari.

Ms. Casey attended Bread Loaf Writers' Conference at Middlebury College in Vermont, where her teacher was poet Robert Frost. She received a master's degree from Middlebury in the 1940s.

She also studied at the William Butler Yeats School in Sligo, Ireland, and took courses in English at Oxford University and George Washington University, philosophy at Catholic University, Italian at Georgetown University and Spanish at Boston University.

She moved to Silver Spring in 1941 and taught English at Sherwood High School from 1941 to 1945.

For the next 23 years, she taught at Bethesda-Chevy Chase High School, where she was chairman of the English department. In 1965, Yale University named her one of the four best secondary-school teachers in the United States. She retired in 1968 so she could see more of the world.

A former student recalled in a newspaper profile of Ms. Casey that "she had a strong aura of authority in the classroom but never raised her voice. She was always available to students, but never 'chummy.' "

During the 1970s, she taught English to immigrants from Vietnam, China and Cambodia, working with her students individually on the front porch of her Silver Spring home. In the 1980s, she taught a young woman from Iran and two doctors from Mexico. Throughout her retirement, former students dropped by to visit; many came from across the country to attend her funeral.

In 1999, at age 91, she visited Norman, Okla., on a 3,000-mile cross-country trip. One of her former students, David L. Boren, the former U.S. senator who had become president of the University of Oklahoma, arranged for her to speak at a luncheon at the university.

During his congressional career, Boren had made it a point to invite Ms. Casey to be in the audience whenever he and his colleagues were scheduled to vote on significant legislation. He had dedicated a park bench to her on her 88th birthday, with a brass plaque honoring the teacher who had been the most inspirational of his life.

Being a teacher was "the only thing I ever wanted to do my whole life," Ms. Casey told the Bethesda-Chevy Chase student newspaper in 1998.

Survivors include her sisters, Eleanor M. Casey and W. Doris Poole, both of Silver Spring.

Margaret Casey studied abroad, taught English to immigrants and was honored by Yale University.