The one on the left is Seohyun, the Maknae 또는 the youngest . The 다음 one is Taeyeon the leader. 다음 one is Hyoyeon the dancing queen. The 다음 one is Yoona the face/visual. The 다음 one is Yuri, she's the black pearl. The 다음 one is Jessica the ice 퀸 and she was born in America. The 다음 one is the shortest, Sunny. The 다음 one is Tiffany the eye smile and the English speaker, she was also born in America in the same hospital as Jessica. And the last one is my favourite, Sooyoung she is my favourite as well.
Annyeong ^^ Left to right : Seo Joo Hyun / Seohyun - Maknae , Lead Vocalist , sub-dancer Kim Taeyeon - Main Vocalist , Leader Kim Hyoyeon - Main Dancer , Main rapper , vocalist Im Yoona - Face of the group , Lead Dancer , Lead rapper , vocalist Kwon Yuri - Lead Dancer , Lead Rapper , Vocalist Jessica Jung ( former member ) - Main Vocalist , English speaker Lee Sunkyu / Sunny Lee - Lead Vocalist Hwang Mi Young / Stephanie 또는 Tiffany Hwang - Lead Vocalist , English speaker Choi Sooyoung - Lead Dancer , Lead Rapper , Vocalist 8 in our eyes , 9 in our ( SONES - fanclubs name ) Hearts