was an Edo period scholar of the kokugaku tradition and one of the most eminent scholars of Japanese grammar. He made the first serious attempt in Japan to classify the words of the language according to their grammatical functions.
He analysed Japanese poetic language and did work in periodising Japanese (ä¸Âã¤ä¸Âã»ä¸ÂæÂÂã»ä¸Âé Âã»è¿ÂæÂÂãÂȋÂÂã¨ã¤ä¸Âã»ä»Âã®ä¸Â, or "ancient ages", "middle old days", "midd-time", "close old days", "past ages" and "present ages"). He is best known for setting up four "parts of speech" in Japanese based on an analogy with clothing: na (names = nouns, indeclinable), kazashi (hairpins = particles or connectives), yosà Âi (clothing = verbs), and ayui (binding cords = particles and auxiliary verbs). This division can be found in Kazashi shà  (ãÂÂæÂ¿é ÂæÂÂãÂÂ, 1767), and corresponds to Ità  Tà Âgai's division into jitsuji (å®ÂÃ¥ÂÂ), kyoji (èÂÂÃ¥ÂÂ), joji (å©åÂÂ) and goji (èªÂè¾Â) as described in Sà Âko jiketsu (ãÂÂæÂÂè§ÂÃ¥ÂÂ訣ãÂÂ).
He later published Ayui shà  (ãÂÂèÂÂçµÂæÂÂãÂÂ, 1778), where he put emphasis on yosà Âi and azashi/ayui rather than on na, and describes the system of particles. First he makes a division of particles that can go with nouns and particles that can't. The first group then divides into tagui (å±Â) â sentence-ending particles, and ie (å®¶) â particles "inside" a sentence. The second group divides into tomo (å«) â particles of tense and mood, tsura (éÂÂ) â inflexible suffixes, and mi (身) â other particles. Fujitani is describing both kazashi and ayui (together) as "kotoba wo tasukuru mono" (things that help the words). This work includes also the study of katsuyà  (conjugation of predicatives). Pointing out the word order and relations of words and sentences is considered one of his greatest contributions to the study of Japanese grammar.
Fujitani's older brother (in law) was another famous kokugaku scholar Minagawa Kien (çÂÂå·Âæ·ÂÃ¥ÂÂ, 1735âÂÂ1807), author of ãÂÂå©åÂÂ詳解ãÂÂ.
His work was studied during the bakumatsu era by Yasuda Mitsunori (å®Âç°å ÂÃ¥ÂÂ, 1797âÂÂ1870), but not fully appreciated until resurrected by the grammarian Yamada Yoshio (1873âÂÂ1958).
Source: ãÂÂæÂ¥æÂ¬èªÂè¦Â説ãÂÂï¼Âã²ã¤ãÂÂæÂ¸æÂ¿ï¼Â, 2007 (14th ed.)
https://web.archive.org/web/20090615060813/http://www.tufs.ac.jp/ts/personal/kudohiro/gakusi.html