Korean words dog and crab are spelled differently but both are supposed to be pronounced the same like the English word "gay" in modern standardised Korean
historically and in some local dialects they are pronounced differently
The number four in native Korean should be pronounced like the English word "Nate" but is pronounced like the English word "net" by many or maybe even most Korean speakers
This is related to the same compund vowel as the previous example with dog vs crab