sentences:  He died in Jerusalem.His main achievement was the "Études de syntaxe copte" published in 1944 which fundamentally changed the scientific view of the syntax of the Coptic and earlier ancient Egyptian languages.Polotsky's theory of the Egyptian verb (a particularly delicate argument, since Egyptians distinguished their different verb forms mainly by the vocalizations, and vowels were not written) had so much success that it has been called the Standard Theory.