I got interested in this area because unquestionably, learners of English should not learn only grammar and vocabulary but they also have to concentrate on pronunciation. As the main medium of communication or the language of the world. As noted by Crystal (1997: 106), the English language is a dominant language and a vital means of communication for millions of people around the world in scientific, technological, and academic areas. Thailand has long recognized the importance of English as a means to strengthen its capacity in the competitive world. The Ministry of Education has a policy to include English in all school curricula, aiming essentially to enhance learners’ ability in mastering the structures and basic vocabularies of the English language.