How do I pronounce 협력? Are there any rules that apply to it to change its immediately apparent pronunciation?
Yes. 협력 is pronounced 혐녁.
This is the result of a combination of some standard pronunciation rules:
- ㅁㄹ => ㅁㄴ sound change
- A 받침 of any of the closed-lip consonants (ㅂㅃㅁㅍ), followed immediately by an ㄹ, will cause the ㄹ to be pronounced as an ㄴ.
- ㅂㄴ => ㅁㄴ sound change
- A 받칩 of ㅂ followed by any of the nasal consonants (ㅁㄴ) will cause the ㅂ to be pronounced as an ㅁ. (Like in 합니다)