Idiom Formation and Derivation; Productivity

There has been a tendency in the technical literature of linguistics to confuse idiom formation and derivation. It is important for us to understand clearly not only the distinc­tion between these two, but also the reason for the confusion.

To start with, we need the notion of productivity. The productivity of any pattern — derivational, inflectional, or syntactical — is the relative freedom with which speakers coin new grammatical forms by it. Thus the formation of English noun-plurals with [z, s, ə z] is highly productive. The addition of -ly to produce an adverbial is fairly productive; the addition of -dom to form a noun from a noun is quite restricted.

The productivity of a pattern varies in time: some of out freer patterns were highly limited five hundred years ago, and conversely. There are also shorter-termed variations of the sort we might call “fashion”. For example, twenty-odd years ago, when the type of restaurant called a cafeteria was spreading across the country, there was a short explosion of similarly-formed names for stores in which there was an element of self-service: groceteria, booteteria, booketeria, and so on, to a total of well over a hundred, most of which are now completely in limbo.

Setting such brief fads aside, we find that, by and large, syntactical patterns tend to be the most productive, inflec­tional patterns next, and derivational patterns least.

It also appears that, the less productive a pattern is, the more likely it is that if a new form does get coined by the pattern it will have idiomatic value. We do have idioms involving highly productive patterns: e. g., the coast is clear. But it is relatively difficult to create a new idiom by the subject-predicate pattern, as in the instance just given. On the other hand, consider the English derivational suffix -ward or -wards. We inherit a double-handful of perfectly ordinary words containing this suffix: northward(s), and so forth with names of compass-points, inward(s), backward(s), sunward(s). We do not freely say such things as He walked tablewards or on my Chicagoward journey. Therefore, when P. G. Wodehouse wrote Lord Emsworth ambled off pigwards, the stretching of the pattern beyond its ordinary limits achieved some sort of special effect: pigwards was a new idiom.

In the above we see one reason why there has been the confusion between derivation and idiom formation: derived stems are often idioms, and newly-created derived stems tend to have idiomatic value because of the relatively un­productive nature of the majority of derivational patterns. Clearly, however, the association, between idiom formation and derivation is not identity. Derived stems are not always idiomatic; idioms are not always derived stems. Currently the formation of adjectives with a suffix [-ı j] is rather productive: one hears new combinations like Chinesey, pavementy, New Yorky, and even phrase derivatives like a paper-boxy sort of contraption — the forms are highly collo­quial and do not turn up in print. But they are not idioms: the special value adheres to the suffix, not individually to each new combination. Awful is both a derivative (stem awe- and affix -ful) and an idiom. Darts, as the name of a game, is an idiomatic fixation of the ordinary plural of the noun dart, and is thus an idiom but not a derivative. [...]