"Think of words ending in -GRY. Angry and hungry are two of them. There are only three words in the English language. What is the third word? The word is something that everyone uses every day. If you have listened carefully, I have already told you what it is."
This is the riddle in its original form going back 20 years - so it's been around a while.!! The answer is 'WHAT' - I'm not being rude by shouting Nigel, this is just to show the answer.
Very well done, Cetti, to get the 'original'. I always thought the 3rd word was LANGUAGE. But really after 20 years I think this puzzler has had his/her 15minutes of fame. Digressing; What about those Cottingley Fairy kids who kept their secret for 60yrs and even fooled Conan Doyle?
You're right xyzzy - I made a right hash up in my answer. What I should have said was - in the original Q the answer is LANGUAGE, but how Nigel phrased it the answer is WHAT. In effect, there is NO right answer!
The excellent World Wide Words http://www.worldwidewords.org/articles/gry.htm
has not only a discussionof the various versions of the riddle, but also 9 more words ending in -gry. Well worth a look.