Dionysius Thrax (Διονύσιος Θρᾷξ) (170 BC‑90 BC) was a Hellenistic era Greek grammarian who lived and is thought by some to have worked in Alexandria and later at Rhodes.

He wrote the first extant grammar of Greek, "Art of Grammar" (Tékhnē grammatiké). It concerns itself primarily with a morphological description of Greek, lacking any treatment of syntax. The work was translated into Armenian and Syriac in the early Christian era.

Thrax defines grammar at the beginning of the Tékhnē as "the practical knowledge of the general usages of poets and prose writers." Thus Thrax, like contemporary Alexandrian scholars who edited Attic Greek and Homeric texts, was concerned with facilitating the teaching of classic Greek literature to an audience who spoke Koine Greek.

References

• Dionysios Thrax, Art of Grammar
  
• Robins, R. H. A Short History of Linguistics (Indiana UP, 1967). (ISBN 0-253-35210-X)
  
• V. Di Benedetto, "At the Origins of Greek Grammar," Glotta 68 (1990): 19-39.
  
• J. Lallot, La grammaire de Denys le Thrace (CNRS Editions, 1998).

Dionysius Thrax (in Greek)