Even the best of writers have particular grammatical weaknesses in their writing that need to be corrected before their books are printed. If your word-processor has a grammar checker, it is a great idea to use it before you finalize your book. It will help you spot potential problems like over-long sentences, awkward syntax, missing verbs, and other errors. The latest versions of Word have very good grammar checkers which I find very helpful. One warning, just because the word processor suggests it, don’t accept it on face value because they don’t work with certain technical manuscripts. But even with their limitations they can be a very helpful tool. Keep writing!