Through the history of modern English, countless verbs have been recruited into service as nouns through a natural process known as "functional conversion". As John McWhorter explains, many of the inflections that differentiated among the lexical categories of Old English have disappeared from the language; consequently, we cannot expect the parts of speech of "Our Magnificent Bastard Tongue" to be as inviolable as those of most Indo-European languages:

The linguist notes that in a language with a goodly number of endings showing what part of speech a word is, making a noun into a verb means tacking the appropriate ending onto it. In French, the noun "copy" is copie; the verb "to copy" is copier. But in a language like English with relatively few endings, making a noun into a verb requires no extra equipment, and so copy just becomes copy.
No one, as far as I know, has advocated the prohibition of this practice. Even Dean Alford, who took a generally dim view of the nineteenth century erosion of The Queen's English, saw it in a positive light:
I do not see that we can object to this tendency in general, seeing that it has grown with the growth of our language, and under due regulation is one of the most obvious means of enriching it.
Today, the verbing of nouns, even proper nouns, is commonplace and generally goes unquestioned. (Personally, I don't mind being Googled, but like most men, I cringe at the thought of being Bobbitted.) The only point of contention, it seems, is Alford's requirement of "due regulation". As Bernstein observes, the conditions under which nouns legitimately become verbs are not always clear-cut. While he is critical of writers "who delight in novelty and who attempt conversions regardless of whether there is any use for them ... who would elevator themselves to their penthouses, get dinner-jacketed, and go theatering", Bernstein concedes that "there is a continuing need for new words either to express succinctly new situations or to express old situations that otherwise require the expenditure of too much verbal effort." He proposes two criteria:
One test, therefore, is the test of necessity: Does the word fill a need? The only other test is whether the word has established itself. This does not mean whether a large number of avant-gardists are using it, nor whether a large number of supermarket checkers are using it, but rather whether it is in normal use among speakers and writers of taste.
Gilman's commentary on the matter is puzzling. On the one hand, he seems to recognize some variants of Bernstein's criteria in his arguments for allowing verbs such as debut (it "comes in handy in newspaper and magazine articles") and chair ("dictionaries accept the term without comment. It is standard."). On the other hand, he insists that any noun-verb conversion is as valid as any other, regardless of whether any such conditions are met. Thus, the common objection to the verb gift "does not stand up ... against the many noun-verb pairs that draw absolutely no critical attention whatever". Anyone who disagrees with him, Gilman asserts, is "linguistically unsophisticated".

Similarly, McWhorter argues that to reject any such conversion is to reject them all. To those of us who don't "like" the verb impact, for example, he retorts, "Well, okay—but that means you don't 'like' the use of view, silence, worship, copy, outlaw, and countless other words that started as nouns and are now also verbs." Here the linguist has ventured beyond his area of competence into the esoteric realm of my personal preferences. As it happens, I am quite comfortable with view as a verb, although I might have felt differently had I been around in the sixteenth century to witness the transformation. The conversion of worship also occurred sufficiently long ago that it sounds like a verb to me, although I recognize this as an unfortunate result, since the word is unmistakably inflected as a noun, McWhorter's analysis notwithstanding. For while it is true that English is not an overtly inflected language, it is equipped with a number of derivational morphemes that serve the distinct purpose of generating nouns. Among these is the suffix -ship, dating back to Old English, which is commonly appended to a noun to form a second noun, denoting, for example, the condition of being that which is expressed by the first, as in friendship, or its rank or position, as in ambassadorship. Thus, worship was originally a contraction of worthship, denoting the condition of deserving or being held in esteem, long before acquiring its modern meaning.

Would the linguists really have us live in a world deprived of dedicated nouns? Certainly there are some that defy verbification. Consider the case of a phrasal verb, such as lock down, collapsed to a single word to generate a noun, lockdown. Occasionally, such a noun is misused as a verb in place of the original phrase, as in "How to lockdown your Facebook account for maximum security", or "USPS will pickup your packages for free", or "The best time to workout is when you are most awake." Do the descriptivists mean to defend such convolution? (For a thorough discussion of this phenomenon, see loginisnotaverb.com.)

As for impact, McWhorter is right—I don't much like it in its neologistic sense of affect, since it offers no apparent advantage over the latter. However, it is fairly well established as a verb with the older meaning to pack or drive close (especially its past participle, often used in reference to teeth), and is probably a lost cause. Still more offensive is the verb interface, which I frequently hear in the workplace. The American Heritage Dictionary, however, whose usage panel "has been unable to muster much enthusiasm for the verb", assures me that "it never really caught on outside its niche in the computer world, where it still thrives", and where, I might add, there is little hope for redemption. Our conservational efforts may be spent more fruitfully elsewhere.

I cannot think of a noun less suitable for verbification than leverage. This is a candidate that violates every criterion for convertibility—a poster child for mistreatment of the parts of speech.

The English noun lever is the equivalent of the French leveur, derived from the infinitive lever, "to raise". The suffix -age, coincidentally, is also of French origin, first appearing in Middle English in words inherited from French: voyage, entourage, homage, language, baggage, marriage, passage, carriage, menage, cartilage, etc. Eventually, the suffix itself was absorbed into English and used in the formation of new words, invariably abstract nouns but variously denoting, for example, a process (coverage, drainage, steerage), the cumulative result of a process (wreckage, shrinkage, assemblage), a charge for a service (postage, towage, wharfage), or a state of being (peonage, bondage, outage).

Leverage is the mechanical advantage gained by the action of a lever, i.e., the ratio of load (output force) to effort (input force). By metaphorical extension, the word is commonly used to denote any analogous amplification of a resource, especially in the realm of finance in reference to the use of credit to enhance an investor's speculative capacity. Like many nouns (such as impact and experience), the conversion of this one began with a participle, with the coining of the term leveraged buyout to describe the acquisition of a company by another with borrowed funds, using the combined assets as collateral. Full-fledged verbification quickly ensued, as in "Learn how to leverage your mortgage debt."*

When a word emphatically announces its nounhood with a suffix intended solely for that purpose, shouldn't this predilection be respected? Of course, there exist English verbs far older than leverage that are inflected as nouns, including some with the same morphemic suffix. In some cases, contrary to McWhorter's observation, the extension took place in the original French ( voyage, ravage, homage); in other cases, it occurred only in English (damage, pillage, salvage, package). However regrettable this trend may be, each of these words is well established and universally accepted as a verb. This is not true of leverage. Although its use as a verb has spread beyond the field of finance, it is still found preponderantly in the business world, a demographic segment in which "speakers and writers of taste" are a rarity at best. Moreover, even this limited usage is relatively new, having made its first appearance in the OED in the 1988 printing of the Second Edition. It probably began as an American innovation, but even the American Heritage did not acknowledge it until 1982.

Furthermore, the new verb fails Bernstein's "test of necessity". Any need for a verb to describe the action of a lever or the use of leverage is already served by lever itself, which, although also brought into the world as a noun, has been well established as a verb since the nineteenth century and is quite adequate for the purpose. (When I presented this argument during a barroom discussion with my friend Tim Buchowski, he responded with this limerick.)

What accounts for the growing currency of a verb that defies established usage and rules of construction, offers nothing in the way of expressiveness, and is rejected by reputable writers? Sometimes the value of a word lies not in its utility in conveying information, but rather in its failure to do so. This may be desirable either because the speaker wishes to conceal relevant information or because he simply has none to convey. One way to achieve this result is to use a noun in place of a verb. When we say that X interfaces with Y, we are saying, presumably, that there exists an interface between X and Y, but we have avoided saying anything about what X actually does. To lever undoubtedly means to apply a (perhaps metaphorical) lever, but when the verb is used transitively, there is no telling whether the direct object corresponds to the effort or the load.

To leverage, on the other hand, has no discernible meaning at all. It is not difficult to find occurrences of the verb that are variously intended to mean "use", "apply", "solicit", "influence", "maintain", "borrow", "acquire", "sell", "impose", or "enhance", as well as occurrences, both transitive and intransitive, to which it is impossible to attach any meaning whatsoever:

  • "8 Ways to Leverage [use] Social Media Beyond Social Networks"
  • "Seeking a position where I can leverage [apply] my broad knowledge of business intelligence, financial reporting, project management, and software development to lead and plan the analysis, architecture and development of software solutions to answer business challenges"
  • "Blagojevich used state programs to leverage [solicit] support for new tax."
  • "We began to leverage [influence] policy makers and political leaders to draft legislation."
  • "15 Ways to Leverage [maintain] Your Liver's Health"
  • "It makes sense that strapped middle class families would leverage [borrow?] up more than flush rich ones, but that doesn't imply an obvious role for inequality."
  • "We proposed an innovative spin on our mobile-based app to leverage [acquire] policy support for integrating this product in the NYC DOE."
  • "There has always been a market for stolen data. Today, the speed at which that information gets leveraged [sold] is astounding."
  • "Conditionality refers to the use of financing to leverage [impose] policy reform, that is, to impose particular policies, which need not be the policies that would freely be chosen by the recipient."
  • "It makes more sense to be able to leverage [enhance] what we do in a more effective way to our listeners."
  • "Marxist economic policies are neither leveragable [??] nor sustainable, as evidenced by the collapse of the Soviet Union, followed by no resulting global economic impact from that loss."
  • "Pabrai's apparent willingness to invest in leveraged [??] situations where a major loss is possible has caused some to argue that he isn't really a value investor."
  • "No details were given of how the 440 billion-euro European Financial Stability Facility might be altered although French Finance Minister Francois Baroin used the word "leverage" [??] in comments to reporters."
  • "The Seminar featured strategic partnership development and engagement frameworks that EDC would leverage to broaden its strategic partnership initiatives and enhance operational efficiencies." (In spite of repeated attempts to read this sentence, I never made it to the end.)
In short, to leverage is to perform an action, virtually any action, but usually one that reveals the cleverness of the performer. Not only is this verb eschewed by writers and speakers of taste, but if not for the financial, business, and corporate pioneers of its usage and their insipid followers, it would find no use at all. Nonetheless, the McWhorters and the Gilmans, if they have not already done so, will soon be telling us that its propriety is affirmed by the illiterates who propagate it. Have we no choice in the matter? Perhaps not, but Orwell's advice regarding abuse of language is as relevant as ever:
One cannot change this all in a moment, but one can at least change one's own habits, and from time to time one can even, if one jeers loudly enough, send some worn-out and useless phrase—some jackboot, Achilles' heel, hotbed, melting pot, acid test, veritable inferno, or other lump of verbal refuse—into the dustbin, where it belongs.