Quiz of the day

Quiz - Generally speaking words that end in y when pluralized adhere to the rule take off the y and add ies. pony=ponies What common words can you think of that do not follow this rule? I can only think of 2 right off hand and they are related. Day and Holiday. Maybe it is the whole ay thing. fray and frays tray and trays woo woo I think I am on to something. But really, let me know if you think of something different.