Originally Posted by gmw
More seriously, doesn't they and their etc. cover most of the requirement?
I've seen they/their quite often used here on this forum and every time stumbled over it as it was followed by the verb in its singular form. For a non-native speaker it sounds soooo wrong - we are glad to get at least the basics of grammar right. It took me a very long time to realise how they/their is meant and that this was just another case of political correctness (and, of course, we do have the same problem in German too!).