As a native english speaker, I never really thought about what “is” really meant, but after starting to learn some other languages, I saw how often times, expressions with “is”, were often, in the other language, used as expressions with “have”. For example: EN: I’m cold. FR: J’ai froid.
This started to make me wonder what “is” actually meant. At first I though that is could just be a synonym to “equals”, but that doesn’t always work. (E.g. “He is sad”. Not, “he equals sad.”)
As of now, I have two theories as to what “is” means.
The first is that sometimes “is” can be equated to “equals” (e.g. January 15th is today.) It would be strange to say that January 15th equals today -and that statment would only be true one day of the year-, but technically, I think, that would be a correct logical statment.
The second is that “is” can also mean “the subject of this sentence currently manifests/embodies the abstract concept about to be listed” (e.g. He is sad.” would follow this definition.)
What I am wanting to know is whether -and I assume that this list isn’t complete- there are other definitions or stipulations concerning what “is” means.
As Wittgenstein put it,
Meaning is one of the words of which one may say that they have odd jobs in our language … What causes most trouble in philosophy is that we are tempted to describe the use of important "odd-job" words as though they were words with regular functions.
As it happens, only what linguists call lexical words have meanings. Many other words don’t have meanings so much as they have uses. They’re basically part of the grammatical rebar that’s supporting all those meaningful lexical words in the sentence.
They’re machinery, these words, and they don’t have any meaning. So it’s pointless to argue. Words like the and of and there and than; and, most relevantly, be, in all its forms, in many uses.
The overwhelming majority of occurrences of be in English come from one of four constructions:
- auxiliary verb for the Progressive construction: Bill was leaving at 5.
- auxiliary verb for the Passive construction: Bill was shot at 5.
- auxiliary verb for all predicate adjectives: Bill is sick/dead/here/hungry/tall.
- auxiliary verb for all predicate nominals: Bill is a doctor/the man to see/who she mentioned.
Furthermore, even when be is the only verb in the sentence, it still behaves like an auxiliary verb.
- He is going ~ Is he going?
(auxiliary verb undergoes subject-auxiliary inversion in question)
- This is the one she saw. ~ Is this the one she saw?
(this be also behaves like an auxiliary)
In fact, no form of be behaves like a real lexical verb, and therefore it has no lexical meaning. Speakers of languages without a copula, about half the people in the world, aren’t surprised.