(Nantana Sittirak and Suthida Pornjamroen, 2009)The samples consisted of 400 students from Chiang Mai University, KhonKaen University, Srinakharinwirot University and Prince of Songkla University at Trang Campus. They found students whose participants had problems with British and American spelling, vocabulary classification, and meaning at a high level. The result of this research almost students have a lot of understanding about the vocabulary but some students give incorrect answer in some question.