North Koreans and South Korean use difference expression and words in the same situation

Koreans use the same Korean alphabet, but there is a big gap in communication, because North Koreans and South Korean use difference expression and words in the same situation.

For example, North Koreans say "It is stinging(Ttagapda)" when they touch hot water.
South Korean say "It is hot(Tteugugda), when they touch hot water.

Koreans will have much difficulty in communication after the unification.

http://www.rfa.org/korean/weekly_program/kim_chon_ae/SeoulThinking-07082016105916.html