A Korean letter is Hangul. ㄱ ㄴ ㄷ ㄹ ㅁ ㅂ ㅅ ㅇ ㅈ ㅊ ㅋ ㅌ ㅍ ㅎ are consonants and ㅏ ㅑ ㅓ ㅕ ㅗ ㅛ ㅜ ㅠ ㅡ ㅣ are vowels.
Consonants:
ㄱ sounds like g.
ㄴ sounds like n.
ㄷ sounds like d.
ㄹ sounds like l.
ㅁ sounds like m.
ㅂ sounds like b.
ㅅ sounds like s.
ㅇ doesn’t have any sound when it comes first and sounds like ~ng when it is at the bottom.
ㅈ sounds like j.
ㅊ sounds like ch.
ㅋ sounds like k.
ㅌ sounds like t.
ㅍ sounds like p.
ㅎ sounds like h.
Vowels:
ㅏ sounds like a.
ㅑ sounds like ya.
ㅓ sounds like u.
ㅕ sounds like yu.
ㅗ sounds like o.
ㅛ sounds like yo.
ㅜ sounds like oo.
ㅠ sounds like yoo.
ㅡ sounds like eu
ㅣ sounds like i
There are some mixed consonants and vowels.
ㄲ sounds like gg.
ㄸ sounds like dd.
ㅃ sounds like bb
ㅆ sounds like ss.
ㅉ sounds like jj.
ㅐ sounds like ae
ㅒ sounds like yae
ㅔ sounds like ae
ㅖ sounds like yae
ㅚ sounds like oi
ㅙ sounds like oae
ㅟ sounds like we
ㅞ sounds like wae
ㅢ sounds like eui
ㅝ sounds like wu.
Now we are going to make a letter.
ㄱ + ㅏ = 가 (ga)
ㄴ + ㅏ = 나 (na)
ㄷ + ㅏ = 다 (da)
ㄹ + ㅏ = 라 (la)
ㅁ + ㅏ = 마 (ma)
ㅂ + ㅓ = 버 (bu)
ㅅ + ㅓ = 서 (su)
ㅇ + ㅓ = 어 (uh) (If ㅇcomes at the beginning of the letter it has no sound.)
ㅈ + ㅓ = 저 (ju)
ㅊ + ㅓ = 처 (chu)
ㅌ + ㅗ = 토 (to)
ㅍ + ㅗ = 포 (po)
ㅋ + ㅗ = 코 (ko)
ㅎ + ㅗ = 호 (ho)
ㄲ + ㅜ = 꾸 (ggoo)
ㄸ + ㅜ = 뚜 (ddoo)
ㅃ +ㅣ = 삐 (bbi)
ㅆ + ㅣ = 씨 (ssi)
ㅉ + ㅡ = 쯔 (jjeu)
Here is a basic letter chart.