why am i taking an ESL4 class?

My english skill is not really good, and I need to improve it very well because I want to find a good job in the future. Living in the US, people speak English, I also want to communicate with them using with excelent english speaking. hopfully, I will get better after I finish all the ESL classes. There is no doudt because i have to get good grades of any final tests, so i need to study hard.