Complex sentence: Heo Ga-yoon (born May 18,1990) is a South Korean idol, singer in the South Korean girl group, 4Minute and its associated duo 2Yoon, formed by Cube Entertainment in 2009.
Split into simpler sentences: Heo Ga-yoon (born May 18,1990) is a South Korean idol, singer and a member in South Korean girl group, 4Minute. She is also associated in their sub-unit group, 2Yoon, which consists of duo in the group, formed by Cube Entertainment in 2009.