Recently, I have been using HelloTalk quite frequently. I realised that Koreans use the phrase 그렇군요 (geu-reo-gun-yo) often. Since then, I have been using this phrase during my communications with them. This is an example of how I used the phrase.
Friend: We have about 15 – 20 days of annual leave each year.
Simple! Just use 그렇군요 instead of ‘I see’ or ‘Oh I see’. So go forth and use it. 🙂