In 1897, Seo Jae-pil was sent into exile to the United States, and Ju Sigyeong left the newspaper.

Interested in Western linguistics and teaching methods, Ju Sigyeong served as a Korean instructor for the American missionary William B. Scranton, founder of today's Ewha Womans University.

Ju proposed that the Korean parts of speech include nouns, verbs, adjectives, adverbs, unconjugated adjectives (관형사; 冠形詞), auxiliaries (조사; 助詞), conjunctions, exclamations, and sentence-final particles (종지사; 終止詞).

In his 1914 publication, Sounds of the Language (말의 소리), he promoted writing Hangul linearly rather than syllabically.

This is one of his few proposals not to have been implemented in modern Korean linguistics, although there have been experiments with linear Hangul, most notably in Primorsky Krai.