Heinrich Gottfried Ollendorff (1803, Rawicz near Posen – 3 April 1865, Paris) was a German grammarian and language educator.
Ollendorff is heavily indebted to an early 'modern method' teacher, Jean Manesca, who appears to have written the first fully developed modern language course in the early 1820s—designed for French, Ollendorff was keen to see it adopted for the classics, and actively promoted the idea. His Oral system of teaching Living Languages Illustrated by a Practical Course of Lessons in the French through the medium of English was entered at the library of Congress in 1834.
In his introduction, on pg xix, Manesca writes,
If I have not spoken of the advantages that may be derived from the present mode of teaching applied to dead languages, it is not because I entertain the smallest doubt of its efficacy in that particular; for, on the contrary, I am confident that many years of toilsome, tedious, and almost fruitless labours, would be saved by the adoption of such a method for these languages. A well disposed young man, between eighteen and twenty, well versed in the principles of his mother tongue, would, in twelve months, acquire a sufficient knowledge of Latin or Greek for all the purposes of life. Such a consideration well deserves the attention of the few scholars competent for a task which would prove so beneficial to the present and future generation of collegiate students. The present modes of teaching the dead languages are sadly defective. It is high time that a rational, uniform method should be adopted.
Shortly afterwards, Henri Ollendorff adopted Manesca's methodology, and produced series of books using the 'Ollendorff' method, which follow Manesca extremely closely.
In the 1840s Ollendorff also wrote the first post-renaissance textbook for conversational Latin, the Nouvelle methode pour apprendre, a lire, a ecrire et a parler une langue en six mois, appliquee au Latin. Ollendorff's French text contains little on grammar, and is almost entirely intuitive, with learning based on practice alone, not theory. George J. Adler's American edition is an extensive revision of Ollendorff's first attempt, including grammar; this version of the Ollendorff text has 600 pages of very fine print, with copious exercises. Adler also expanded and re-wrote the Latin text, resulting a much higher quality textbook, with more elegant Latin, and a wider variety of examples based on the historical classic sources.