Hangul 3 : 5 Double Consonants (자음)

     There are 5 double consonants which is the double of ㄱ, ㄷ, ㅂ, ㅅ and ㅈ. The double consonants are pronounced without any air release and tensified in the throat.

ㄲ   (ssang-giyeok)   ~>   kk 

ㄸ   (ssang-digeut)   ~>   dd 

ㅃ   (ssang-bieup)    ~>   pp 

ㅆ   (ssang-siot)       ~>   ss 

ㅉ   (ssang-jieut)      ~>   jj