Learn some words using Hanja! These words use Chinese words as a basis so a lot are related and use the same syllables. Which makes them easier to learn and remember their similar meaning.
Similar to “un-” words in English (unhappy, unclear, unknown, unusual, uncomfortable) you know all of them have the meaning of “not- this thing”.
If you’ve learned some words associated with school or education like 학교 you might have noticed the reoccurring 교 theme, that’s because a lot of school and educational words use Sino-Korean!
Let’s get into some Sino-Korean with the 인 from 인간! 인간 is derived from the Chinese character 人 which means person. This is one if the simplest characters with minimal strokes and it looks like a stick mans legs so it’s easy to remember!
Sino-Korean basically means that a specific words source is originally Chinese. About 60% of Korean has Chinese origins as a basis. Words like 인간 (person/human) use the Chinese character (or hanja in Korean) 人 make the 인 in 인간.
I remember really having an issue with sino vs native korean numbers and this is a recourse I found that can really help you out if you find yourself in the same position! You can play through 1-100 on both the sino and native korean numbers games for a nice review and test on your skills.