Can anyone tell me, please, what (if any) reference book or website editors use as the "Bible" of grammar and punctuation? I have heard the Chicago Style Manual cited by American editors and agents, but would like to know what to use over here. Thank you.
I've got an old Oxford English Grammar by Sidney Greenbaum, that I find is still up to date. But as others' have said, look for apps on your phone or on your computer. Many universities have online guides, complete with exercises. Bristol University has one of the simplest to use.
There is also 'The Student's Guide to Writing' by John Peck and Martin Coyle. Very straightforward, inexpensive.
Like Lorraine says, always get the latest edition.
There are many free phone apps for grammar and punctuation. Some have tests to improve your writing skills. You will find the apps on google play. Select the most downloaded apps, or the ones you consider most useful to meet your requirements.
I hope that helps.