Stationery and stationary: which is which? One of them is a noun, used to describe things like envelopes and writing pads, the other is an adjective meaning “not moving”. Many adults have problems with these words so it’s understandable that children do as well. Even if you know the difference, how do you remember, and how can you teach it other people? Here’s one way.
Stationery (envelopes and writing pads) is sold at a stationer’s, so that’s the word that ends with “ery”. Similarly, a confectioner sells confectionery and an ironmonger sells ironmongery. Think of the people who traditionally owned and ran the stores (stationer, confectioner, ironmonger) and stick a “y” at the end.
Stationary (not moving) is an adjective, so it ends in “ary” like all common adjectives with the same sound (ordinary, primary, secondary, tertiary, complimentary, necessary).
There are adjectives that end in “ery” but they all derive from a noun ending in “er”: shivery, blubbery, jittery (which could have been three of the names rejected in Walt Disney’s “Snow White and the Seven Dwarfs”).
I thought that stationery and stationary was the only combination that could be confused in this way. Like desert and dessert (which I wrote about in this piece from last year) there are no other examples that you can use to generalize. You can’t establish a series of rules for similarly misspelt pairs of words. It turns out, though, that “confectionary” is a word. Dictionary.com defines it here as “a place where confections are kept or made”. It is also defined as an adjective, “pertaining to or of the nature of confections or their production”. The spell-check in Microsoft Word did not correct it, but here in WordPress the word is underlined in red as a misspelling. It looks wrong to me. Ironmongary, on the other hand, looks wrong and is wrong. It’s not a word.
Just to keep it simple: a stationer sells stationery, a confectioner sells confectionery and something that’s not moving is stationary.