Abeghyan returned to Tiflis in 1898 and was immediately invited to teach at the Gevorgian Seminary, which he accepted. In 1898, he completed the voluminous work (Legends of the Armenian people in Movses Khorenatsi's History of Armenia), which was directed against the arguments made by
Grigor Khalatiants about
Movses Khorenatsi's History of Armenia. Abeghyan began cooperating with
Komitas on the compilation of Armenian songs and published two collections of fifty songs each; another set of fifty songs remained unpublished. Starting in 1906, Abeghyan began publishing a series of articles titled "" (The Armenian folk epic) in the journal (Ethnographical journal), continuing his study of the epic
Daredevils of Sassoun on the basis of fifteen versions of it. In 1906, Abeghyan completed his influential grammar of modern Armenian titled . In 1907, he wrote a grammar of
Classical Armenian, which later served as the basis for his two-part textbook of Classical Armenian, published in Tiflis in 1915–16. Abeghyan's Armenian textbooks were widely used in the Armenian schools of the time. In 1913, a
critical edition of Khorenatsi's
History of Armenia, which Abeghyan and Set Harutyunyan had been preparing since 1901, was published in Tiflis. In June 1914, Abeghyan resigned from his positions at the Gevorgian Seminary and moved again to Tiflis. He became the teacher of Classical Armenian and old Armenian literature at the
Nersisian School. He gave public lectures on old Armenian literature, folklore and epics. He also taught at the newly established Armenian State Gymnasium in 1917. In 1918, preparations began in Tiflis for the foundation of a university in Yerevan for the newly independent
Republic of Armenia. Abeghyan was appointed a member of the organizing committee, and the following year he was invited to Yerevan to teach at the newly opened university. On 1 August 1919, he was appointed a professor and dean of the Faculty of History of
Yerevan University. At the request of the Union of Armenian Lawyers and Tiflis, Abeghyan,
Stepan Malkhasyants and a group of lawyers prepared a Russian-Armenian legal dictionary, the first of its kind, which was published in 1919. A year later, Abeghyan was invited to work in the Ministry of Justice of Armenia to further develop Armenian legal language. In June 1920, Abeghyan took up the position of head of training courses for military officers. After this, Abeghyan and a group of military specialists were tasked by the Armenian ministry of defense with developing military terminology in Armenian. Abeghyan continued this work after Armenia became a Soviet republic, compiling a Russian-Armenian and Armenian-Russian dictionary of military terms and overseeing the editing of military books and records.
Spelling reform Abeghyan was a leading figure in the
reform of Armenia orthography which was carried out in Soviet Armenia. Abeghyan had advocated for spelling reform earlier, having given a lecture about its necessity in Etchmiadzin in 1913. The goal of the spelling reform was to bring Armenian orthography up to date with the pronunciation of the modern language. He was tasked with developing the new Armenian orthography by the Soviet Armenian ministry of education. He outlined his suggestions in a public lecture in Yerevan in 1921, proposing to carry out the spelling reform gradually over the course of several decades. Instead, the reform of Armenian spelling was implemented immediately, provoking criticism from part of the Armenian intelligentsia both in Armenia and in the diaspora. Abeghyan defended the new spelling against its critics in two books. In 1940, the final round of spelling reform was implemented based on Abeghyan's proposals from 1921, establishing the orthography that is used in Armenia to this day.
Career in Soviet Armenia In 1921, Abeghyan was elected a member of the Armenian Relief Committee, aimed at improving the humanitarian situation in Armenia. Abeghyan continued his teaching activities at Yerevan University, lecturing on Armenian folklore, old Armenian literature and the Armenian language. He became associated professor in 1921 and full professor in 1926. In 1923–1925, he served as dean of the historical and literary faculty of the university. In 1925, the first research institution of Soviet Armenia, the Institute of Science and Art, was founded. Abeghyan was elected its vice-president. He continued his research activities while holding these administrative and teaching positions. In 1931, he published a new version of the book (Theory of the Armenian language) and the monograph (Old bardic folk songs). He was elected a member of the Central Executive Committee of Armenia in 1925, 1927, and 1929 and was elected to the Transcaucasian SFSR Central Executive Committee in 1929, and before that, in 1927, a member of the Yerevan City Council. In 1930, he was suddenly dismissed from the position of the president of the Institute of Science and Art. He then became a member of the presidium of the Institute of History and Literature. In 1932, he was elected chairman of the commission for the correction and creation of place names of the Armenian SSR, which had the task of replacing non-Armenian place names in the republic and adjusting others. In 1935, he was awarded with the title of Honored Scientist of the Armenian SSR and received the degree of Doctor of Social Sciences. In 1931, due to an eye disease, Abeghyan retired from his teaching position at Yerevan University, but he continued his research. During this time, he focused on the completion and printing of his unfinished works. In 1933, he published the study (Metrics of the Armenian language). He particularly focused on the Armenian national epic, agreeing to edit a critical edition of
Daredevils of Sassoun together with Karapet Melik-Ohanjanyan. This edition was published in 1936. On August 22, 1939, at the jubilee session of the Armenian branch of the USSR Academy of Sciences dedicated to "Davit of Sassoon", he read a report, which was entirely devoted to the examination history of the writing, publication and study of the novel in Armenian philology. Abeghyan's report was published in Armenian and Russian under the title "Bibliography of the Armenian folk epic
David of Sassoun."
Last years and death Abeghyan's health deteriorated again in his later years. He refused several offers to return to teaching at the university. He dedicated his efforts to organizing the large collection of Armenian folklore and songs, which he undertook forty years before with Komitas and left half-finished. In 1940, he published a large collection of Armenian folk songs called s and a collection of medieval urban lyrical songs. In the spring of 1940, despite his poor health, he began work on the a critical edition of
Koriun's Life of Mashtots on the occasion of the 1500th anniversary of the death of
Mesrop Mashtots, the inventor of the
Armenian alphabet. The edition was published in 1941 with Abeghyan's translation into modern Armenian, preface and notes. One of Abeghyan's last major works was (History of ancient Armenian literature), which covered Armenian folklore and literature from its origins up to the 10th century. After completing the first volume, he moved on to work on the second volume covering the period up to the 14th century. This was published in 1946 after his death. Abeghyan died on 26 September 1944 in
Yerevan. He is buried at Tokhmakh cemetery in Yerevan. == Family ==