Textbook vs Real
Textbook이것은 무엇입니까i-geos-eun mu-eot-im-ni-kka
Real뭐야 이게mwo-ya i-ge
Why Koreans say it this way
Universal K-drama reaction. 뭐야 (casual "what is it") with 이게 (this thing) after — reversed word order for emphasis. The textbook version 이것은 무엇입니까 sounds like a science textbook. Real shock reverses subject and predicate.
From: K-Drama Common