becoming; the act or fact of becomingThis is the verb 되다 (“to become”) in the present attributive form 되는 plus 것 (“thing”), which nominalizes the verb. In everyday speech, 것은 is often contracted to 건 and 것이/것을 may become 게/걸 depending on the particle. 되는 거 is a casual spoken form of 되는 것.