Why do we add S to some words but ES to others? And when a word ends with Y, how do we know whether to change the Y to I before adding the plural suffix? And why on earth does knife become knives? You can unravel these mysteries with six simple rules.
Still not sure which word to use? Choose a picture and take a look through the many choices! This graphic has excellent pictures to go with the information and I think that really help gets the point across. Anna comments: expansion of vocabulary