^You'll learn! Don't worry. I took me a really long time to tell the members of kpop group Rainbow apart. It was so difficult for me xD
Maybe this picture will help you:
http://fyafterschool.tumblr.com/post...l-for-the-saem
From left to right: Bekah (she graduated though

) - Raina - Jungah - UEE - Kahi - Nana - Lizzy - Jooyeon - E-Young
I hope it helps! Just keep looking at pictures and the members' profiles