A successful career often requires the ability to write well. In order to convey your ideas clearly, you need to know grammar. Having good grammar skills helps you not only to write better but also to leave a better impression on your readers.
If you are a beginning learner, Basic Grammar Step by Step is a great book for you. The book uses a systematic approach to teach basic grammar.
If you are an intermediate or an advanced learner, there is the downloadable Focus on Grammar series that you can download. Each book in the series focuses on a particular grammar topic, with ample examples of correct and incorrect sentences. When you finish a book, you will have a good grasp of the topic you previously had trouble with.
