Adult ESL courses through community centers or private classes usually do not require any formal education or completion to a particular grade or level. Any non-English speaking adult can apply to and attend these courses provided they can pay the tuition costs if applicable.
ESL courses are an important part of learning to live in an English speaking country. Instead of approaching English as another language to learn, these courses help to present the material the way that most learn it as a child, in a simple straight forward method. It's a great way to learn a new language.