Read often. One essential key to learning and understanding proper English grammar is to read. Reading books, whether fiction or non-fiction, is paramount to identifying the intricacies of English grammar. By reading often, you'll learn to understand common themes in where and how grammar is used by experienced writers.
Study a grammar guide or English language book. Studying a grammar guide or book on the English language is imperative to landing a firm grasp on the language. Books such as "The Elements of Style," by William Strunk and E.B. White help provide a natural flow in written words so that they sound natural and pristine.
Take an English language course or class. If English is not your native language, taking an English course can help to focus your understanding of grammar. These classes exist to assist students who speak English as a foreign language to gain a better grasp on grammar and the language as a whole. Instructors of these classes are often well versed in a multitude of languages.
Find a tutor. Tutors are sometimes an essential part of learning as they can provide assistance in difficult studies, including English grammar. Unlike an English class, tutors take a more personal approach and will assist you on a one-on-one level. A tutor who speaks fluent English can assist in proof-reading your writing and offer advice and tips you might not otherwise be aware of.