O'Grady 2019, there are four basic deictic demonstratives in Jeju. Most other sources mention three, which are identical to those of Standard Korean. Proximal: "this" Medial or absent: "that" Distal: "that" Vocabulary Most of the Jeju lexicon is Koreanic, and "a sizeable number" of words are identical with Korean. There are false friends between the languages, such as Korean "to wash hair" and Jeju "to wash the body." Jeju also preserves many Middle Korean terms now lost in Korean, such as "wife; woman" and "parent." Like Korean, Jeju uses many Sino-Korean words based on local readings of Classical Chinese. Jeju Island was ruled by the Mongols in the late thirteenth century and some Middle Mongol terms still survive in the language, though the extent of Mongol influence is disputed. Popular claims of hundreds of Mongol loans in Jeju are linguistically unsound. Uncontroversial Mongol loans are most common in terms relating to animal husbandry. Jeju may have loans from an ancient Japonic substratum. As the last fluent generation of Jeju speakers were born under or shortly after Japanese rule, remaining speakers also use many loans from Modern Japanese. Sound symbolism Jeju has widespread sound symbolism in ideophones. The use of sound symbolism to form emphatic variants of words is more common in Jeju than in Seoul Korean. Jeju sound symbolism operates with both consonants and vowels. The intensity of a Jeju word may be strengthened by using tense and especially aspirate obstruents. The sound symbolism may also be emphasized through the addition of consonants, by adding the sequence to both reduplicated segments, and with fortition or lenition. The yang harmonic class of vowels has a bright, small connotation, and the yin vowel class gives a dark, large connotation. Ko Jae-hwan also gives examples of three or four layers of vowel sound symbolism. Consonant sound symbolism: "savory" → "[very] savory" → "[extremely] savory" "[small] sound of rat gnawing teeth" → "[large] sound of rat gnawing teeth" "easily angered" → "[very] easily angered" "neatly aligned" → "[very] neatly aligned" Vowel sound symbolism: "round [of a small object]" → "round [of a large object]" "[small and light] sound of muttered complaints" → "[large and heavy] sound of muttered complaints" → "[very large and very heavy] sound of muttered complaints" "smooth to the touch [of a very small or dry object]" → "smooth to the touch [of a somewhat small or dry object]" → "slippery