Koreans don’t say “Umm” | Korean FAQ
A quick way to tell if someone is a native Korean speaker or not, is to pay attention to whether or not they use sounds such as “umm” or “uhh” often when speaking. This isn’t to say that Koreans don’t make these sounds (they do), but they often use different sounds than in English.
This video will share some alternate sounds that you can make when you’re thinking to sound more like a native speaker.