Okay, thank you!

From https://en.wikipedia.org/wiki/Korean_phonology Korean consonants have three principal positional allophones: initial, medial (voiced), and final (checked). The initial form is found at the beginning of phonological words. The medial form is found in voiced environments, intervocalically and after a voiced consonant such as n or l. The final form is found in checked environments, such as at the end of a phonological word or before an obstruent consonant such as t or k. Nasal consonants (m, n, ng) do not have noticeable positional allophones, though ng cannot appear in initial position. ㄱ Initial allophone : k ex) 가을 Medial allophone : ɡ ex) 사과 Final allophone : k̚ ex ) 직진 ㄷ Initial allophone : t ex) 다음 Medial allophone : d ex) 지도 Final allophone : t̚ ex) 닫기 ㅂ Initial allophone : p ex) 바다 Medial allophone : b ex) 가보 Final allophone : p̚ ex) 답가 ㄹ Initial allophone : ɾ ex) 리본 Medial allophone : ɾ ex) 나리 Final allophone : l ex) 솔개 Listen and repeat https://www.youtube.com/watch?v=0ZhOeA0RD9o

As a native Korean speaker, I agree with Gertie's succinct and well-informed comments.

The sounds of English and the sounds of Korean are different. Therefore, you can't just pick one English letter to match with one Korean letter. Also, English pronunciation/orthography is ridiculous, so it's all very debatable.

Learn how the letters /sound/ by listening, not reading. Don't worry about Romanization. Very inaccurate and subjective. Actually, somebody just asked this exact Q the other day. You could look for it (I'm on my phone).