I notice this problem all the time doing Korean courses, but I would bet it also happens in Chinese, Japanese, and other languages with characters that represent whole syllables. I have noticed that when I make a mistake in the first syllable of a word, it is marked red, but in other positions of the word, the same degree of error will be marked yellow.
Let me try to explain the issue with an example:
Say my word is 폭력. (pok-lyeok)
Suppose I enter 푹력 (puk-lyeok). This would be marked as red wrong.
But suppose I enter 폭략 (pok-lyak). This would be marked as yellow wrong.
(Similar things happen with longer words too, I just notice it the most in 2-syllable words because both ways it’s 50% wrong.)
Both of these answers really should be marked as yellow wrong (and it would be great if Memrise could tell the difference between a whole wrong syllable in hangul and just one wrong letter, but I realize that’s probably too much to ask). Having mistakes in the first syllable marked as red wrong causes a lot of over-repetition in a course over time.