Yale romanization of Korean

The Yale romanization of Korean was developed by Samuel Elmo Martin and his colleagues at Yale University about half a decade after McCune–Reischauer. It is the standard romanization of the Korean language in linguistics.

The Yale system places primary emphasis on showing a word's morphophonemic structure. This distinguishes it from the other two widely used systems for romanizing Korean, the Revised Romanization of Korean (RR) and McCune–Reischauer. These two usually provide the pronunciation for an entire word, but the morphophonemic elements accounting for that pronunciation often cannot be recovered from the romanizations, which makes them ill-suited for linguistic use. In terms of morphophonemic content, the Yale system's approach can be compared to North Korea's former New Korean Orthography.

The Yale system tries to use a single consistent spelling for each morphophonemic element irrespective of its context. But Yale and Hangul differ in how back vowels are handled.

Yale may be used for both modern Korean and Middle Korean. There are separate rules for Middle Korean. Martin's 1992 Reference Grammar of Korean uses italics for Middle Korean as well as other texts predating the 1933 abandonment of arae a, whereas it shows current language in boldface.

Yale writes basic vowels as a, e, o, and u. Vowels written to the right in Hangul (ㅏ, ㅓ) are written as a or e, and vowels that are written below (ㅗ,ㅜ,ㆍ, ㅡ) are o or u. Yale indicates fronting of a vowel, written in Hangul as an additional final stroke ㅣ, with a final -y. Palatalization is shown by a medial -y-.

Although Hangul treats the rounded back vowels (ㅜ, ㅗ) of Middle Korean as simple vowels, Yale writes them as a basic vowel (ㅡ, ㆍ), combined with a medial -w-.

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