Grammar course?

0I’m wondering if there is an accredited English grammar course online or through distance learning. As a non-native speaker, I find that knowing grammar (or as I see it, the “structures” of the language) very helpful. Currently, I study grammar through books (these books are usually found in the “linguistics” section of the bookstore and are usually quite expensive). Though the subjects covered are quite ‘deep’, I actually find it rather interesting and very helpful in appreciating the language. 0-