Dear,

Word power Made Easy by Norman Lewis is a Very good book to improve your Vocabulary. High school English grammar and Composition by Wren & Martin books are also very famous. It basically consists of the manual of English grammar and Composition. These two authors contributed their work in improving the English knowledge among people. Prefer as per your Capability and understanding. To me Norman Lewis always focus on improving our vocabulary. To improve your Vocabulary follow Norman Lewis books. For grammar you can follow wren martin books.