ʼPhags-pa inspiration for Hangul hypothesis

The Korean alphabet is known as Hangul internationally, Hangeul in South Korea, and Choson'gŭl in North Korea. There are a number of uncertainties about the origin of Hangul, especially how the shapes of its letters were conceived. Some scholars have argued that the ʼPhags-pa script of the Mongol Empire served as a minor inspiration for the shapes of several consonant letters of Hangul.

Several Korean scholars hypothesized that the ʼPhags-pa script inspired aspects of Hangul in the centuries after Hangul's 1446 promulgation. In 1957, Canadian linguist E. R. Hope became the first to explore possible graphic correspondences between the letters of ʼPhags-pa script and Hangul. American Koreanist and linguist Gari Ledyard submitted a Ph.D. thesis in 1966 (revised in 1998, additional explanatory paper published in 1997) in which he evaluated and expanded upon Hope's analysis.

Hope tries to derive the shapes of 10 Hangul letters from ʼPhags-pa letters. Ledyard argues some of these derivations are contrived; he instead tries to derive only 5 or 6 basic Hangul letters, some in a different manner to Hope. From there, he derives most of the other consonants by following a modified version of a stroke addition rule that allows for subtraction of strokes. That stroke addition rule was introduced in the text Hunminjeongeum Haerye, which introduced Hangul.

These hypotheses are less popular than the hypothesis that Hangul was largely an original invention. They have received a range of reactions from scholars. Some have expressed support for parts of or the entire hypotheses, some argue such hypotheses cannot be ruled out, and some argue they are implausible.