Generally, or at least in my experience, 'to be' is introduced as a verb.

But is it? It doesn't appear to describe a change as in 'I kicked a ball' or 'he picked the pen up'.

It describes things as they are as in 'this ball is blue', and how they will or might be without being specific how that state will be reached: 'this ball will be blue' or 'this ball might be blue'.

But it does describe the whole state, but a quality of it; which is consonant with its adjectival description: 'the blue ball'; but notably this is without tense.

We could, though say 'bluish'; so speculatively we could posit an adjective, derived from blue, and when used signifies 'not blue now but will be blue in the future'.

This suggests that 'is' is a linguistic element that says that a particular quality subsists in some object; in essence then, it describes states and not actions.

Is this right?

  • Your question was answered from a variety of domains. Menzenski's recent answer was particularly astute and exhaustive. But it would be most interesting to know which one was most satisfying to YOU -- ie best addressed the specific concerns that motivated you to ask it.
    – gonzo
    Dec 8, 2015 at 1:12
  • @gonzo: They all were, in one way or another; my concern was to elaborate on the distinction between motion and rest; but not in nature, but in language ie action and state. One might, I suppose call it an aspect of human nature but directed to general things. Dec 8, 2015 at 1:40
  • Call what "an aspect of human nature?" The distinction between motion and rest, action and state (?) as "directed to general things?"
    – gonzo
    Dec 8, 2015 at 2:21
  • You may be interested is this wikipedia entry : en.wikipedia.org/wiki/E-Prime
    – Kii
    Dec 8, 2015 at 13:31

8 Answers 8


Yes "is" is a verb in natural language. There is a distinction, grammatically, between transitive and intransitive verbs.

  • Transitive: He kicked the ball.
  • Intransitive: He blushed.

"Is" is intransitive. Note too that "is" has distinct uses.

  • Predicative: The ball is blue. (This fits what you say above best.)
  • Categorizational: A square is a rectangle. (Note, not rectangular.)
  • Existential: "The blue ball is." (More idiomatic in contemporary English would be "the blue ball exists," but the existential is is genuinely grammatical.)

As far as I know the verb for to be can be used in each of these separate ways in English, German, French, Latin, Ancient Greek and Hebrew. I can't speak to other languages, but I imagine there are similar uses.


What is true of words denoting one sort of concept is not always true of words denoting other sorts of concepts, even if they are generally considered to have the same 'part of speech'.

For instance, the progressive is X-ing construction sounds just fine when used with some verbs (John is running, Kate is writing), but odd, if not downright ungrammatical, with others (*Melinda is believing his story, *Steve is knowing the answer).

The word is is likewise compatible with the progressive only in some contexts: both José is silly and José is being silly sound okay (albeit not equivalent), but between That is my car and *That is being my car, only the former is acceptable.

In a broad sense, we can categorize words into three semantic groups: words referring to objects, words referring to properties, and words referring to actions. While these three groups generally align with the commonly used parts of speech terms noun, adjective, and verb, an approach based on semantics and actual usage rather than prescriptive rules makes a finer-grained classification possible.

Just as we have three basic semantic groups, we might propose three basic sorts of usage. We may want to make outright reference to a concept, or we may want to invoke one concept to modify another, or we may want to predicate (or assert) a concept.

The three semantic categories are not limited to specific sorts of usage, but there is clearly one sort of usage where each is best-suited, or prototypical in a linguistic sense.

Objects, like DOG, TABLE or CAR, are usually time-stable — they persist from moment to moment in a way that properties (e.g., SHORT) and actions (e.g., JUMP) do not. They exist out in the world and can usually be counted. They're prototypical referents. This prototypicality is reflected in the wider range of grammatical options available to them in the reference function. We can refer to property words and event words, but we have to mark them explicitly. We have to add a noun-making suffix -ness to refer to the property word dark (Darkness is unpleasant), and the suffix -ing or the infinitive marker to to refer to the action word run (I like running / I like to run). We don't need any such modification for more prototypical object words — in fact, there are additional linguistic strategies available when referring to object words: we can make them plural, for instance, or use articles. Compare I like dogs with *I like darknesses or *I like runnings — only the first sounds okay. Again, while we can usually make a plural of a non-prototypical referent, it takes more effort, and the meaning won't necessarily be the same: I like several sorts of darkness.

Properties, like YOUNG, FAT, BLUE, likewise show a preference for one sort of construction: modification. No special marking is necessary to indicate that a property word is serving a modifying function: the red car, the young girl. Object words and action words can be used for modification, but they need to be marked for that function by additional linguistic form. For example, possessive 's is one way to mark an object word for modification (the man's car), while -ing can signal that an action word is modifying a referent (the sleeping girl). In both cases, words denoting non-prototypical properties need extra marking. (In linguistics this sort of extra marking is called 'structural coding'). Similarly to how only more prototypical object words can inflect for plural number in English, more prototypical property words also have additional 'inflectional potential' available to them when serving a modifying function: they can inflect for degree through suffixation: young, younger, youngest, fat, fatter, fattest, blue, bluer, bluest (or through suppletion: good, better, best). Less prototypical property words can still mark the comparative, but they have to do it with a separate word: nuanced, more nuanced, most nuanced, not nuanced, *nuanceder, *nuancedest (stated another way, these property words demonstrate the greater inflectional potential of property words in a modification function, but at the same time they need greater structural coding to express that potential). Object words and action words used for modification can't express this inflectional potential at all: *the man's-est car, *the car most of the man, *the sleepingest girl.

Considered in this light, the word is is a verb in that it is part of a predicating construction, but both its function and its range of 'inflectional potential' and 'structural coding' differ greatly depending on the semantic class of the word it occurs with:

  • When it occurs with more prototypical action words (i.e. 'verby verbs'), it indicates the progressive (John is running) and may be used to mark the passive voice (That book was read by Maria). It may also be left out entirely; when that happens (e.g., John runs), the construction denotes a regular or habitual action.

  • When it occurs with less prototypical action words (i.e., 'not-quite-as-verby verbs'), particularly verbs denoting mental processes or mental states, it can't indicate the progressive but it can be used to mark the passive: *Jake is liking his new apartment sounds strange, but The answer was known by Tanya sounds okay.

  • When it occurs with property words (i.e., 'adjectives'), it may be used with or without progressive marking, but be is really the only word with which it can be used: Marek is silly means that we're ascribing him a general characteristic (i.e., it's not necessarily that his behavior in the present moment gives that impression), while Marek is being silly means that we're making a statement about his actions right now. Properties which are construed as 'permanent', 'inherent', or 'involuntary' are difficult to use with a progressive construction: *Marie is being French, *Alex is being hungry, and *Zendaya is being tall all sound awkward at best. The passive construction is also not available to property predicates: *Silly was been by Marek sounds very ungrammatical. When property words are predicated, they are marked with greater structural coding which action words don't require. The word is is that extra coding. Note, though, that when used in predication property words are able to express some of the inflectional potential of action words: the progressive is possible, but the passive isn't.

  • Finally, when used with object words (i.e., 'nouns'), the progressive generally isn't allowed: *This is being Tom, *John is being a doctor. In these constructions, the word is is really serving as the greater structural coding which is necessary to predicate an object word. Unlike predicated property words, however, predicated object words don't really have access to any of the inflectional potential of predicated action words. In other words, by these criteria we'd be justified in saying that 'properties are more action-like than objects', or 'adjectives are more verby than nouns'.

We can even use the relations between these semantic groups and functions to describe a conceptual space (this diagram is from William Croft's Typology and Universals, p. 187). In this diagram, the cells along the upper-left-to-lower-right diagonal express the most prototypical combinations of semantics and usage, and the cells furthest from that axis express the least prototypical combinations.


             object   ______object  ______object
OBJECTS      reference      modifier      predication
               |              |             |
               |              |             |
               |              |             |
             property ______property______property
PROPERTIES   reference      modifier      predication
               |              |             |
               |              |             |
               |              |             |
             action   _____action  _______action
ACTIONS      reference     modifier       predication

What it all comes down to, I suppose, is what your definition of is is. For me, neither 'is is a verb' nor 'is isn't a verb' does a good job of describing what the word does.

(For a much more detailed treatment of this approach to language, see the works of William Croft, particularly the monographs Typology and Universals and Radical Construction Grammar.)

  • +100: this is a great answer; it's a pity I can't accept more than one, and I've already accepted one. Dec 8, 2015 at 1:42
  • 2
    @MoziburUllah I think you can undo the acceptance of an answer and accept another one
    – miracle173
    Dec 8, 2015 at 5:00

In general "to be" is not an autonomous but an auxiliary verb. It links a noun with a property. The latter can - but need not - denote a state. Hence "to be" denotes a relation between two objects, it is considered a copula.

Autonomous verbs denote an action either in active or passive form. A limiting case are verbs like "to sleep" or "to lie on the ground".

"To be" in the meaning "to exist" is the only use of "to be" as an autonomus verb. It took some time in the European philosophy of language until the two different types of "to be" were clearly separated. Even some passages in the late works of Plato mix both meanings, which led to philosophical pseudo problems.

The first European philosopher who investigated in a systematical way the use and the different meanings of "to be" (Greek einai) was Aristotle in his The Categories.


Not all verbs express actions or changes. For example, "Bob appears well", "Douglas lies at the confluence of the Dhoo and the Glass", "Carol stands between Bill and Daniel", "this piece of cheese smells off".

But "is" is certainly quite versatile in English. Frequently it is part of an auxiliary verb and often it is used to expresses a quality or a subclass. There is a lot more information in the Wiki page on the copula.

As to its possible philosophical significance, some have suggested distinguishing two different forms, one for things that exist (or are extant) and one for more general use that could be applied to non-existent objects. See for example, the section on dual copula in the SEP article on non-existent objects.


This is more a linguistic question than a philosophical one (unless I've missed something in the question beyond a purely definitional "what is a verb and is 'is' one?")

In semantics we treat the copula as semantically vacuous: it doesn't add any meaning. In lambda notation, it is "lambda x. x". Thus, when deriving the semantics of "the ball is blue", "is blue" collapses to just "blue", which is usually treated as a set, and the meaning of the sentence becomes "the ball is a member of the set of blue things". The only exception I can think of is the floating existential is, as in "the world is", in which case one would use the lexical entry that means the same thing as "exists". But this is a different use of the word.

In syntax, when a language has a copula (most languages don't), it occupies the head of the verb phrase because as a part of speech is considered to be a verb.

Thus, as far as linguistics is concerned (and correct me if I'm mistaken in taking this question to be one of linguistics), is is a verb.

  • Check out the end of Wehlers answer; having said this, my question has hardly brought out its philosophical significance in this way. Dec 8, 2015 at 1:10

I would agree with your analysis, and I would say that 'is' as a verb is more of a quirk of Indo-European languages than a reflection of the true meaning of "is". Consider the example you gave, but translated in Arabic: "The ball is blue": Al-kura zarqaa. "The blue ball": Al-kura al-zarqaa. The two sentences are almost the same, save for the additional definite article "al-". So basically, the meaning of "is" can be conveyed without really resorting to any action.

What would be really interesting is to see what effect the perception of being as a from action has had on Indo-European cultures?


A slight dissent. While technically "to be" is a verb, Kant argued that it is not a proper predicate. When we say that X "exists," we add nothing to "X." When we say "X is blue" we simply assert a "blue X."

He used this to refute the presumed affirmation of the subject in the ontological proof of God. We might easily imagine a language without such a verb or copula, and I do not think it is at all universal.

I believe Heidegger claimed that "being" was an original, unique feature of ancient Greek language, and attributed great significance to this, presumably in formalizing the categories of ontology. Perhaps others can correct me or expound.


My understanding is that words called "verb" convey actions, occurrences, or states of being. So our grammatical conventions say it is a verb. But, technically, it is interesting to note (in the context of King's answer, and the supposed "paradox of analysis"), that you did not ask whether "to be" is a verb, but whether 'is' is.

  • King is right; however, I asked it in that form because I liked how the first is, was followed by a second is. Dec 8, 2015 at 1:05

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