Expanding on past my Batchim post here, let’s get into why sometimes ㄱ/ㄷ/ㅂ pronunciation can sound like their more stressed heavier forms ㄲ/ㄸ/ㅃ depending on the word. It might seem not very clear but we can break it down and understand it much better.
Why Can ㄱ/ㄷ/ㅂ Sometimes Sound Like ㄲ/ㄸ/ㅃ?
Simply put you’ll typically find the ㄱ/ㄷ/ㅂ pronunciation more stressed when they are preceded by or right after another consonant; except ㄴ/ㄹ/ㅁ/ㅇ/ㅎ. If you’ve been practicing speaking for a while you may notice you have picked up on this naturally with some common words.