Korean is 70% similar to Japanese. The grammar and word order is almost the same.

I don't speak Korean myself, but I've lots of Korean friends in Japan, some of whom speak very well Japanese and English as well, so they explained to me how similiar Korean and Japanese are.

As there are so many dialect of Japanese and that a Aomori-ben speaker wouldn't understand a Kagoshima-ben speaker, I guess some of Western Japan's dialect must be even closer to Korean. Unfortunately, I don't know anyobody who speaks Western Japanese dialects (such as Northern Kyushuu) and Korean. Any Japano-Korean linguists here ?