A dedicated English teacher to “Socratic.org”, a famous academic website to the USA, where teachers of English and Math usually help students, and this advising is always checked by other teachers. Quazi has 11 level of badge for grammar of English.
These common English grammars were being asked by Americans including other 68 country students one by one, and Quazi answered them successfully and more answers will be going on. An E-book will be produced soon too.
The site has been updating, you might wait for a while.