How do I say sorry if you can't understand me in Korean?
Please write in Hangul with accuracy and in both formal and informal way, thank you!I think it is "이해가 잘 안돼면, 제성해여" can you please correct it if it is wrong?

Question

How do I say sorry if you can't understand me in Korean?
Please write in Hangul with accuracy and in both formal and informal way, thank you!I think it is "이해가 잘 안돼면, 제성해여" can you please correct it if it is wrong?

Answer

formal way, 제 말을 이해하지 못하셨다면 죄송합니다. 
and informal way 내 말을 이해하지 못했다면 미안해.