The author may be referencing auxiliary verbs such can/could, will/would, and shall/should. Excepting homophones (e.g. I will myself to run that race every year, I can the best peaches in town), those verbs typically do not carry meaning in and of themselves unless it is supplied indirectly by context.
Do/did is also a common auxiliary verb, but I’m not sure it quite falls into the same bucket as the ones formerly mentioned. Stripped of context and placed outside of a complete verb phrase, do/did is pretty well devoid of meaning - but at least the listener would know some kind of action is indicated, even if imprecisely.
But those are still states of being, albeit a state of mind. They give us information about the object. If someone says “I will run the race”, then any listener will know they are willing. If they say they can run the race, any listener will know they are able. Thus we can see that such verbs do clearly describe a state of being.
How is the verb “to do” not describing an action? :dubious:
I was unclear – without conversational context, those verbs do not impart meaning by themselves the way active and stative verbs can. You can say “I will run the race” and “I can run the race” – but “I will the race*” is ungrammatical in uncontrived contexts.
If a stranger walked up to you out of nowhere and said only “I can”, (or “I will”, “you should”, etc.) and then simply walked off, you’d not have much information about an action or a state of being.
If a stranger walked up to me out of nowhere and said only “I do”, (or “I thought”, “you went”, etc.) and then simply walked off, I’d also not have much information about an action or a state of being. Nonetheless “to do”, “to think” and “to leave” are all verbs that describe states of being. The lack of information supplied by these verbs is because of the lack of context, not because the verbs are inherently vague.
Another way this is often analyzed is by forming imperatives. You can certainly implore someone to “Think!” or “Go!”. “Do!” and “Be!” are dubious stand-alone imperatives, but are almost invariably supplied with objects in actual speech (Mr. Miyagi notwithstanding:D ).
By contrast, “Can!", "Shall!”, and “Will!*” cannot form imperatives.
First off, modals are not verbs in English. Verbs can be governed by modals and modals cannot be so governed. It was once (16th century) possible to say, “I must can…”. Now we have to say "I must be able to…). In both French and German, modals function like verbs. If you want to see this argued in detail, so David Lightfoot’s book, “Principles of Diachronic Linguistics”.
“Do”, aside from being a verb is also a pro-verb. It replaces a verb, similarly to how a pronoun replaces a noun. “Have you eaten?” “Yes, I’ve done it.”
As for the OP, I haven’t any idea how a verb could do anything but describe an action or a state. Of course, you can verb any noun, but then it denotes an action or state.
Admittedly, it’s purely a matter of definition. Grammarians recognize that word categories are fuzzy around the edges. There’s nothing logically inconsistent in flatly stating that “whatever doesn’t describe an action or a state of being ain’t a verb.”
Just because you stick an exclamation point after it doesn’t make it an imperative. The last two sentences They have been shortened for emphasis: [They] Can’t! [They] Can! An imperitive would be “[Hey, you:] Can!” or, in the third person, “[Let them] Can!”
Well, and that is part of the point being made in the blog post quoted in the OP: that the structure of English is gelatinous. “Up” is normally regarded as a preposition (“up the road”), but in this case, it is either being used as an adverb or as an auxiliary component to the primary verb. The latter case might generally be made if examples can be found in other languages where a given construction is embodied in a word that is different from the equivalent of the unmodified verb, or even in English itself (e.g., “put up with” is indivisible, not cognate with its components, and has an English equivalent in “tolerated”).
Wiki adds ‘occurrence’ to state of being or action:
A verb, from the Latin verbum meaning word, is a word (part of speech) that in syntax conveys an action (bring, read, walk, run, learn), an occurrence (happen, become), or a state of being (be, exist, stand).*