Mordechai Schaechter, known by his own wish as Mordkhe, spent a passionate lifetime seeking to resuscitate the Yiddish language of Central European Jewry into a daily means of communication.

It had died a natural death because about half the people among whom it had grown over the centuries from the mixture of German and Hebrew they spoke in their medieval ghettoes, had moved to the US, where their children had swapped it for American English. The millions who remained in Central and Eastern Europe were wiped out in the Nazi death camps.

Today Yiddish is used as the language of instruction in Talmudical colleges which train Orthodox rabbis and teachers, but is rarely spoken outside, even by its teachers and students. But Schaechter’s zeal for the language, kindled in childhood, never cooled and at times turned into an obsession.

When Schaechter began his relentless crusade, the market for Yiddish had shrunk to academia. And there he played a key role in cementing a language that had for centuries been dismissed as no more than a folk dialect, into a subject worthy of academic status on the same level as any other language, be it English, Russian, Arabic or Chinese.

For 12 years until his retirement at the age of 66, he was senior lecturer in Yiddish studies at Columbia University. He taught the language into his seventies at Yeshiva University in New York, at the prestigious Jewish Theological Seminary in that city and at a joint programme run by Columbia and the Yivo Institute for Jewish research in New York; and his academic writings remain on the compulsory reading list of every university Yiddish course.

Schaechter’s work on the standardised spelling of Yiddish, Fun Folkshprach tsu Kulturshprach(From Folk Language to a Language of Culture), published in l999, is regarded as definitive; and he ceaselessly edited dictionaries and journals. He was editor of Yiddishe Shprakh (Yiddish Language), a journal devoted to the grammar, vocabulary and spelling of Yiddish. He was also associate editor of the Great Dictionary of the Yiddish Language, and held the same post for 11 years on [Central European] Jewry.

His bid to seek to make Yiddish a language of daily speech again extended to writing an English-Yiddish dictionary of Pregnancy, Childbirth and Early Childhood and recently Plant Names in Yiddish: A Handbook of Botanical Terminology.

He was founder, director, guru and patron saint of a number of institutions for the promotion of Yiddish, such as the Committee for the Implementation of Standardised Yiddish Orthography, begun in l958, Yugntruf (Call to Youth), set up in l964 to teach Yiddish worldwide, to the Task Force for Yiddish Terminology, founded in l970, and the League for Yiddish set up in l979. No one in that field was as tireless and prolific. Schaechter won great respect and affection, as well as a lasting place in the scholarship of the language.

His children’s telephone answer machines carry messages in both American English and Yiddish, and Yiddish was the only language he spoke with his l6 grandchildren, even though again American English was their natural means of communication. But outside his own family he persuaded few to abandon American English as their daily language.

Schaechter was born into a middle-class family in Czernowitz, a centre of both German and Yiddish culture under the Habsburg Empire. That had been defeated and dissolved some eight years before his birth. By that time it was part of the new Romania under the name of Cernauti and is now known as Chernivtsi and is part of Ukraine.

He survived the Holocaust with his family because the SS did not have a free rein in Romania and his brother-in-law’s status as a doctor gave the family a degree of protection. After the war Schaechter had no wish to live under Soviet dictatorship and moved promptly to Vienna, where he obtained a doctorate in linguistics. He was allowed into the US in l951. Within weeks he was enlisted by the CIA during the Korean War.

Apart from Yiddish, Schaechter was fluent in English and German, and had a working knowledge of Russian, Ukrainian, Polish and Hebrew.

He is survived by Charne, his American-born wife of 50 years, three daughters and one son.

Itsye Mordechai (Mordkhe) Schaechter, linguist and world authority on Yiddish, was born on December 1, l927. He died on February 15, 2007, aged 79