This is the 14524th most frequent Korean word.
물고기가
"물고기가" means "fish" (subject marker attached).
Here, '물고기가' is the subject of the sentence, marked by the subject particle '가', indicating that it is the entity doing the swimming in this context.
물고기가 연못에서 헤엄치고 있어요.
The fish is swimming in the pond.
In this sentence, '물고기가' serves as the subject describing the state of being slippery, leading to the speaker's opinion.
저는 물고기가 매끄러워서 만지는 것이 조금 이상해요.
I find it a bit strange to touch fish because they are slippery.
Here, '물고기가' is again the subject, indicating the entity that has undergone the action of disappearing.