대해 and 대한 are confusing
대한 is an adjective like 경제에 대한 책 means a book on/about economy while 대해 is used when not describing a thing like saying we were talking about economy 우리 경제에 대해 말했어
제 女同生은 世界的인 歷史에 對해 배우고 있어요.
I said, '제 여동생은 세계적인 역사에 관해 배우고 있어요', and it counted me wrong - does '관해' not work in this context?
Please change 세계적인->세계. It is the better word for thus.
sorry, but the goal of this lesson is to introduce '~적인' formula
Why doesn't 배웁니다 work here (instead of 배우고 있어요)?
Adding -고 있다 to a verb makes it continuous.
배웁니다 = "learns"
Here, she is learning about world history, so -고 있다.
배우고 있다 = "is learning"
That's because it's asking you to translate "IS learnING", which means that you need to you the -고 있다 form