Sandra Drake, age 16, of Memphis, Tenn., for her question:

IS ESPERANTO, THE INTERNATIONAL LANGUAGE, CATCHING ON?

Espranto is the most widely used of all the international languages. People in about 90 different countries can speak Esperanto in addition to the language of their own country.

Although thousands of written works have been translated into Esperanto, the language has not received enough international support to indicate that it is really catching on. Experts say that until schools in all parts of the world require students to learn Esperanto, it will not actually become an accepted universal language.

A Polish physician named L. L. Zamenhof devised Esperanto with a book he published in 1887 called "Lingvo Internacia." He wrote the book under the pen name of Dr. Esperanto. The word "esperanto" in that language means "one who hopes."

As other people endorsed the idea of an international language, the popularity of Esperanto slowly grew.

Zamenhof believed that the language would help create good will among nations if people of all countries could learn it in addition to their native language. He believed that a universal tongue would also be a great help to ambassadors, businessmen, tourists and other groups because no interpreters would be needed.

Esperanto has a uniform, simple structure. The accent of a word always falls on the next to last syllable, and each letter has only one sound. Adjectives end in "a," adverbs end in "e" and nouns end in "o." When a noun is used as an object, an "n" is added at the end of the word and plurals end with the letter "j."

The vocabulary of Esperanto is made up mainly of root words common to the Indo European languages. About half of the people in the world now speak languages in this family.

Here's an Esperanto sentence: La astronauto, per specials instrumento, fotografs la lunon. The translation: The astronaut, with a special instrument, photographs the moon.

More than 100 magazines and newspapers are regularly published in Esperanto. Also the language has translations of many classical and modern pieces of literature as well as many religious and scientific books.

A French philosopher named Rene Descartes is believed to have originated the idea of a universal language in the 1600s. More than 200 other languages designed for universal use have been invented since that time.     `

The earliest of the languages to gain much success was called Volapuk. The name comes from two of its words meaning "world" and "speak." Johann Martin Schleyer, a German priest, invented the suggested language in 1879.

Later a simplified form of Volapuk was suggested and became somewhat popular. It was called Idiom Neutral.

Some language scholars say that the world is working by natural process toward an international language. They point out that improved communications are making English almost an international language.