I think the idea of making a grammar check plug-in is too large in scope. Better to have smaller plug-ins that address more specific grammar issues?
I have a few ideas for stuff that could work. What if, every time you used an apostrophe, or you used the word their, you would get a prompt with suggested alternatives? My writers aren’t idiots, they just tend to make the same careless errors over and over. A little alert could help. It could even be programmable from the back end, so that each administrator could load it up with the most common mistakes.
There is a way to hold posts for approval if they have key words in them, but that seems a little drastic.
