Word should have an option for the user to add or delete something to its grammar rules. Adding new words to the dictionary is so useful and it would be great if the user could even choose "don't tell me if Word thinks this is wrong" because it's very annoying when Word is wrong and there's nothing you can do to correct it or make the highlighting go away
We want to let you know that the Word team has heard your feedback and are planning to offer a way to turn off the checking for individual rules in the right click menu in Word 2016. If you’re an Office 365 subscriber, you should see this change in a future update.
Also, for individual cases where you’d like to turn of flagging of a particular issue, you can always click on “Ignore Once” in the right click menu.
As always, thanks for your feedback. We appreciate it!
Leland Beaumont commented
Please allow users to add or modify grammar rules. For example, Stephen King recently suggested dozens of alternatives to the word "Amazing". I want to have that list of suggestions become available when I use the word "Amazing". That feature would be truly amazing.