How can I perfect my English grammer
Be a good reader and you will start to detect common errors quite easily
If based not clear than take J.p.h book or speedy publications. ...than a mirror of common error...
Learning grammar rules from a book helps, but you need to do more. I suggest that you read English books out loud to yourself. I know it sounds crazy, but hearing yourself say things correctly will help you to internalize a language's grammar faster. I've used this method for two languages.
If your basic is cleared then purchase a book thats name is A MIRROR OF COMMON ERROR BY DR. ASHOK KUMAR SINGH