Things That Make English Hard To Speak For Korean Speakers

Korean has a smaller palette of sounds than English and learning new sounds as an adult is difficult. So, it is particularly hard for someone whose first language is Korean to learn to speak English without an accent. There are also some closely related issues:

• Prosody (stress and pitch): Korean is a syllable-timed language.
  • Each syllable in the Korean language is distinctly produced, with equal stress. By contrast, English is a stress-timed language.
  • . . . Korean has less variation in pitch and stress than English.
  • English spoken by Korean native speakers can sometimes be perceived by native English speakers as monotone and monoloud.
• Vowels:
  • There are at least 7 vowels in English that do not exist in Korean: /I/ (as in “bit”), /ae/ (as in “apple”), the “u” sound as in “put”, the “or” sound (as in “for”, “author” and “gnaw”), the /aI/ diphthong (as in “like”), the “or-I” diphthong (as in “boy” or “oil”), and the “au” diphthong (as in “cow” or “allow”).
  • Particular common issues include understanding and producing the differences between:
    • the long “ee” sound (/i/) as in “beet” and the short “i” sound (/I/) as in “bit”;
    • the short “e” sound (as in “egg”) and the short “a” sound (as in apple); and
    • “u” (as in “put”), “or” and “er” sounds.
• Consonants:
  • There are at least 12 English consonants that do not exist in Korean and Korean has fewer consonants that English. Sounds such as /f/, /v/, “th” (voiceless, as in “bath”), “th” (voiced, as in “bathe”), /z/, “sh”, “ch”, “zh” (as in “measure” or “vision”), “j” and “r” don’t exist in Korean. /b, d/ and /g/ are often unvoiced.
  • The Korean consonant /s/* has only a slight air escape, which makes it different from the English /s/.
• Consonant clusters:
  • In Korean, there are no consonant clusters at the start or end of syllables (e.g. like /st/).
  • Many Korean speakers insert a vowel when they pronounce English words including consonant clusters. For example “strike” is sometimes pronounced something like “sitilaiki”.

From here.