Answer:
1. Hangul Pronunciation Changes
2. Carry Over
(If the final consonant (받침) is followed by a vowel it's sound gets combined with the next vowel and it is pronounced as a part of the next syllable & not as an independent character.)
3. Nasalisation
(In Korean phonetic system , ㄴ ㅁ and ㅇ are considered as the nasal sounds. But we must remember that if "ㅇ" is in the initial position it is not a nasal consonant but a null consonant with no sound.)
4. Aspiration
(When a consonant is followed by ㅎ , it gets influenced and changes to aspirated consonant.)