Which nouns can be used as verbs?
Solution 1:
Theoretically, any, absolutely any noun — and indeed any, absolutely any word — in English can be used as a verb. Nothing prevents you from exampling, betweening, egadsing or greating. Theoretically.
In practice, there are of course a variety of reasons why not everything gets verbified. For starters, there are only so many words you really need in everyday conversation. You don't use example as a verb, but you also don't use amaranthine as an adjective. For all you know, both are sitting in a dictionary somewhere, but for all you care, both might as well not exist.
Secondly, there is that linguistic phenomenon called "blocking". We already have the word "to compute", so its existence blocks the verb "to computer" from getting any traction, or indeed from being created in the first place. If it is to be introduced and get any traction, then only in a meaning different from that of "to compute". The difference can be very slight; it can also be one of register or dialect rather than one of meaning, but it will be a difference nonetheless.
Likewise, there is no way to tell what "he examples" might end up meaning should it ever get introduced, but it's likely to be something entirely different from "he demonstrates", or "he leads by example", because we already have other words for those which everybody uses.
Solution 2:
To think that I should have lived to be goodmorninged by Belladonna Took’s son, as if I was selling buttons at the door!
As Gandalf’s exclamatory remark above illustrates, English has no restrictions that preclude some certain class of words, let alone nouns, from being used as verbs.
However, whether your listener or reader will understand what you mean by this innovation is a different matter. This may be especially true if the noun you’re trying to use as a verb is itself already derived from a verb, because people will then have to figure out whether you mean something different than would have been meant had you reverted to the original verb that the noun derived from.
So in the text up to this point, with duplicates removed, we have these candidates:
- to son — ok
- to button — already a verb
- to door — ok
- to remark — already a verb
- to English — ok
- to class — why not to classify?
- to word — already a verb
- to restriction — why not to restrict? how would this be different?
- to noun — ok
- to verb — ok
- to listener — why not to listen?
- to reader — how is this different from to read?
- to innovation — why not to innovate
- to matter — already a verb
- to text — recently verbed
- to point — already a verb
- to people — already a verb
- to duplicate — already a verb
- to candidate — ok
So nouns that are already verbs, or which have base forms that verbs, may be more resistant to verbing. But there is no general rule, because English lets you do whatever you want without whatever you have.
No reason to stop with nouns. Both yessing and to a lesser extent also noing are well attested. From the ever-neologuing world of computer programming there’s anding together two integers, or foreaching across an array, or even withing something. Then of course there’s thouing someone instead of youing or yousing or yalling them.
As for being goodmorninged, that one I’ll leave you to work out for yourself just why it works so well there. See the complete text where Gandalf the Lexicographer (or would that be lexicomancer? :) is trying to work out just what all of Bilbo’s many goodmornings actually mean in context.
Solution 3:
The ratio of words that work as verbs if you put "to" in front of them is much smaller in reality than you might gather from trying a few nouns. I would advise against taking the few examples that do work as anything remotely approaching a rule.
Playful language works in humor, of course, and is enjoyable if done well. But if you do not intend humor, you should strive to learn the language as well as you can manage — and express yourself as unambiguously as the language allows.
For "to example", there is a similar expression: "to demo". This is an abbreviation of "to demonstrate", derived from the noun "demonstration". You show someone an example, usually of a product. The correct verb from the noun "example" is "exemplify".
A good alternative to "to (noun)" is "to use a (noun) to (process)" or "to use a (noun) on (subject/object)".