In an increasingly globalized world, English has become an important in many countries of the world, including Thailand. Teaching English today, Thailand is weak in English language often have harmful effects. In this study I focused on the following question: What is the second language? Why English is very important? Why are Thai students weak in English? The goal of English as a second language education is to help students become proficient in English to develop intelligence and help them achieve the expected learning outcomes according to the course.