This is the 10953rd most frequent Korean word.
금붕어가
"금붕어가" means "goldfish."
Here, '금붕어가' is the subject performing the action of swimming, indicated by the predicate '헤엄치고 있다'.
금붕어가 물속에서 헤엄치고 있다.
The goldfish is swimming in the water.
In this case, '금붕어가' is the subject that initiates the action of creating bubbles, highlighted by the verb '만든다'.
금붕어가 물방울을 만든다.
The goldfish creates bubbles.
Here, '금붕어가' is the subject described by the adjective '조용하다', which states a quality of the goldfish.