What criteria do linguists use to tell if something is a copula?

Let's say there's this group of undocumented languages and a linguist is studying nonverbal predication in those languages.

Language A:

Mary bla-yi   gul
Mary COP-PRES teacher
'Mary is a teacher'

Language B:

Mary sho  gul
Mary 3.SG teacher
'Mary (she) is a teacher.'

Language C:

Mary sh=gul
Mary 3.SG=teacher
'Mary (she) is a teacher.'

Language D:

Mary nun  gul
Mary DIST teacher
'Mary (that) is a teacher.'

Language E:

Mary ha  gul
Mary FOC teacher
'Mary is a teacher.'

We have a variety of items which can pass as copulas because they all seem to be linking the subject with the predicate. Language A has an actual verb (or auxiliary), Language B a pronoun, Language C a proclitic, Language D a distal demonstrative and Language E a focus particle.

Stassen (2013) states that there exist copulas that come in the form of verbal copulas, pronominal copulas, and particle copulas.

Is there a checklist that linguists use to tell if something is a copula? Do linguists identify copulas based on their linking function regardless of their form?

  • The first thing to do is to check if there is not a zero copula. Because copula is not always marked.
    – amegnunsen
    Commented Aug 26, 2019 at 18:16
  • 2
    What definition are you using for "copula" here? That'll affect the answer, because my immediate thought is "it's a copula if and only if calling it a copula makes your model clearer/more powerful/more concise/more elegant/whatever". And that's probably not particularly useful to you.
    – Draconis
    Commented Aug 27, 2019 at 3:44
  • 2
    @Draconis That’s the problem. There doesn’t seem to be a definition. I’d like to know how other people define it too. What we’re used to assuming is that it’s some (usually verbal) element that mediates the relationship between subject and nonverbal predicate and it’s semantically vacuous. So, some of the properties of what can be called a copula would be (A) it mediates the subject and predicate, (B) it’s semantically vacuous. Commented Aug 30, 2019 at 3:00
  • @amegnunsen How do you suggest we do that? Commented Aug 30, 2019 at 3:02
  • @Morphosyntax Added an answer elaborating on that. Basically, "copula" is a hard word to define outside of a particular theory about a particular language—if it connects a subject to a nonverbal predicate, can you give a universal definition of "verb"? If it's semantically vacuous, what do you call the Romance "copulae"? Etc etc. It's one of those words that's useful in a lot of places, but always in slightly different ways, sort of like "adverb".
    – Draconis
    Commented Aug 30, 2019 at 4:13

3 Answers 3


This may not be a satisfying answer (is this becoming a trend with my answers?), but here's the best advice I can give:

A word is a copula if and only if calling it a copula makes your theory more complete, accurate, or elegant.

As you noted in the comments, there's no universal definition of "copula". But even if there were, definitions like this are always difficult to apply cross-linguistically. (Or even within a language! Is running an adjective, or a form of a verb, or an adjective derived from a verb? Different theories give different answers to that question.)

Instead, the definition of "copula" tends to be part of a particular theory, often tied to the particular language you're analyzing. In English, you might define a "copula" as something like "a verbal 'bridge' that connects a subject to its predicate, with no semantic meaning of its own". But this falls apart in various Romance languages, which have two or three "copulae", each with its own semantics. So in Romance, the definition is usually a syntactic one instead: "copulae" are defined by how they act in the syntax, rather than by their lack of semantics.

In the end, copulae are entirely theoretical constructs. There's no sensor we can hook up to a word to determine if it's a copula or not. (Hell, we don't even have a sensor that can tell us whether or not something is a "word"!) So we have to apply the classic rules for testing theories. How well does it explain the data? How elegant is it? How complicated is it? Are there things it can't account for? Because in the end, these questions are more important than any formal definition you come across. If adding copulae doesn't improve the theory, you should always feel free to apply Occam's razor—and excise them completely.

  • 1
    I agree, @Draconis. It's a theoretical word, not a natural phenomenon. Like article or gender, the use of a term that makes sense in one kind of theory, or one kind of language, may be missing from others, or not necessary in describing them, which has the same effect, if one follows Occam.
    – jlawler
    Commented Dec 13, 2019 at 23:32

The most sensical cross-linguistic definition of "copula" is an element that is required for non-verbal predication. The elements in your examples could all qualify as copulas depending on what verbal predication looked like in those languages. That the copula has multiple functions (focus marker, pronominal, etc.) shouldn't affect its categorization.

  • Does that mean that there is no "null copula"?
    – user6726
    Commented Sep 1, 2019 at 0:46
  • 1
    If there is no evidence for a null copula then a null copula should not be posited simply because nothing special is required for non-verbal predication. It makes at least a bit of sense to say that there is a null copula in the present tense for Hebrew and Arabic because a copula shows up in the past and future tenses in those languages. Other, more subtle arguments have been made for a null copula in other languages, but it must be argued for on the basis of evidence and should not be assumed.
    – dkaufman
    Commented Sep 1, 2019 at 1:21
  • You identify it as an element that is required for non-verbal predication, so if it isn't present, I would conclude that it isn't required. I'm trying to figure out why you didn't just stop with 'non-verbal predication', and leave out the required/optional distinction.
    – user6726
    Commented Sep 1, 2019 at 1:25
  • To take the Hebrew/Arabic example again, we would certainly want to call the element that appears in past and future tense non-verbal predication as a copula. It's a separate question if we want to then say that there's also a null copula in the present tense. The question of whether to posit a null element is a very general problem that applies to all types of morphemes. Situations where nulls are posited typically involve paradigms where a category is well attested except under a particular circumstance or inflection.
    – dkaufman
    Commented Sep 1, 2019 at 1:51
  • Take a language that has a rich noun classification system. There are 12 classes, 11 of which are marked by prefixes and one which is not marked at all. It might make sense to say that the unmarked class takes a null classifier prefix, but others would prefer to not posit a null morpheme and say that the unmarked class is simply the default class. In either case it would not affect the analysis of the other 11 classifier prefixes.
    – dkaufman
    Commented Sep 1, 2019 at 2:03

In Arabic , it is true that there is no overt copula in the present tense but there are some features in the system of Arabic that can function as copulas. For example, the indefiniteness of the noun in the predicate can be considered as a kind of copula :

زيد معلم

a teacher Zaid

Zaid is a teacher

When the noun is definite, a copular pronoun ( a pronoun of separation) ضمير الفصل is used :

زيد هو المعلم

the teacher he Zaid

Zaid is the teacher

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.