What is this called grammatically?

If I say - ‘This is not a public company, it is private.’
Instead of saying full - ‘This is not a public company, it is a private company.’

Ellipsis.

No, I don’t think so. Ellipsis involves leaving out words which are grammatically necessary but which are taken to be understood. So if I talk about “the human” or “the forgotten” a noun seems to be required for the adjective to qualify. A word such as “being” or “person” or “people” is taken to be implied; that’s ellipsis.

But in the sentence given in the OP, no word needs to be implied for grammatical completeness. “It is private” is grammatically complete in itself, just like “I am sick” or “the horse is dead”.

Both senses that the OP offers are grammatically complete, and the difference between them is that the first is more concise, and perhaps stylistically superior. But I don’t the difference raises any grammattical issue.

I want to describe what I am saying to another person. It is not an issue, but I think there is a name for it.
I want to show them they cannot just say ‘It is private.’ without the rest of the sentence.

Ambiguous pronoun. Any use of “it” is equally as ambiguous.

The mouse was already sick, and it died of a heart attack when the cat chased it.

The 2nd sentence seems alright with regard to using the adjective ‘private’ naked like that.
That usage is ambiguous as to in what way it is private, but the paragraph would normally be restricted to the one topic ,or at least limit the scope in some way, and its painful to right every sentence like you were drafting legislation or military orders.

I think in your first sentence, the term “private” is an adjective used as an adverb, to describe the company.

The pronoun “it” is used in the same manner in both sentences.

And it illustrates why we all find it difficult and tedious to read and understand original laws and regulations. Drafting these requires the removal all ambiguity which might later be exploited. This applies to punctuation as well - You won’t find commas in a legal document.

I am not talking about pronoun usage. 'Blue Sky is not an ethical company, Blue Sky is unethical. ’ What I am talking about is leaving out the word ‘company’.

How is private being used as an adverb? I see the word being used to modify a noun, thus making the word an adjective.

I don’t think you’re leaving anything out in the second phrase. It’s the first phrase which has EXTRA information. “Blue Sky is unethical, it is not ethical.” No need for “company” at all. You are free to insert it, in either phrase, or both phrases, if you choose to emphasize its status as a “company”…but you don’t have to.

(The redundancy in stating the same thing two ways – “unethical” and “not ethical” --is another issue. Also not a problem grammatically, but usually odd stylistically, again unless you’re choosing to emphasize the point, or if your audience are English-as-second-language learners or children, and you fear they might not understand the word “unethical.”)

“This is not a public company, it is private” is a perfectly legit sentence. The “it” clearly refers back to “this” and the word “private” is an adjective. I don’t think there’s a term for it, because there’s nothing left out.

“Agatha is not the left-handed murderer, she is right-handed.”

So, to answer the question “what is it grammatically?”:
Some sentences have (noun) “is” (adjective), and some other sentences have (noun) “is” (noun). In grade school, I think we called the “is” a “linking verb” (I believe the grownup term is “copula”). In terms of roles in the sentence, the first type is “subject – verb – predicate adjective,” while the second type is “subject – verb – predicate noun.”

A third option is to make a sentence (our clause) with BOTH types: (noun) “is” (adjective) (noun). Technically, it’s a variant of the second type, but really it’s doing the work of both types.

Instead of talking about grammar, I’d like to comment on the meaning of the phrases: “private company” is a legal term, meaning that one cannot buy shares of it in any stock market. But “private”, as used at the end, means low-key and not attracting attention, right?

So if I were to characterize the OP’s sentence, I’d call it confusing, or even misleading.

Not confusing or misleading in this case. The first phrase sets up the implied meaning of “private” in the second phrase to mean “not owned as publicly traded stocks.”

But you’re right, if the whole context were one where there still might be a question about this, best to say “…a private one.”

The phrase you need to explain it to somebody is that you’re using a predicative adjective (link: Predicate Adjectives: Explanation and Examples). They are typically used after pronouns (more precisely, after the verb that you use with that pronoun) and modify the noun that the pronoun refers to.

I think the word you are seeking is incorrect. You should replace the comma with a semi-colon.

:slight_smile:

The part that is left out is understood and assumed to be present for logical reasons. That’s a really simple explanation.

Nah, I’m inclined to agree with Quartz. It trips my “comma splice” meter.

It’s simply replacing a noun phrase with an adjective. “He is a big man.” “He is big.” Both of these sentences mean the same thing, but they’ve simply been written differently, for stylistic reasons.

There is a somewhat outdated way of speaking I hear/read sometimes where the adjective is used as if it were a noun: “Did you see her dress?” “The blue?” Blue is not a noun, but it is used here in place of “the blue one” or “the blue dress”. This seems like a similar issue to the OP’s, but I’m not sure what it’s called.