Quick: How many things are wrong with the above sentence?
Those who know me will not be surprised when I say that it depends on the variety of English you’re using. In casual English, it’s fine, though the speaker may be aware that it’s non-standard (“not good English”). But it presents a few interesting issues. I’m going to start at the end.
I’ll leave off any real address of ending a sentence with ellipses (…), which some people dislike; I used it because I intended it to be “leading,” and that’s different from a flat-out statement.
But there are many people who will insist that a couple things is wrong and should be a couple of things. This is based on couple being a noun. The thing is, though, so is dozen, and we no longer (as we once did) say a dozen of things; so, too, is a million, and actually, in English, so too are numbers generally, though they are a special class of noun. (Numbers are not adjectives in English. Try using them in all the various places where you can use adjectives and you will see that.)
We no longer say a million of people, though we still say a milli0n of them. And couple is coming to be like other numbers, as dozen has and myriad is in the process of doing; you still can say a couple of things, but you can also say a couple things.
Can you say it when there are actually more than two things, as in fact there are with this sentence? Shouldn’t we say several things if there are three or four? Well, if you wish to be precise, yes, but several gives a sense of significant quantity, whereas couple downplays it. Like it or not, a couple is in use as an informal indefinite quantifier. True, it’s a bit weaselly. But English is a very weaselly language – or can be when we want it to be.
The interesting thing is that many of the people who will insist on a couple of will also insist, in this sentence, on There are rather than There’s. Now, if couple here really is a singular noun (like pair or brace), you might think it would take the singular. But of course with collectives we will use the plural when we are emphasizing not the totality but the mass of individuals. So There are a lot of paintings means there are many paintings, but There is a lot of paintings means that there is a lot, probably for auction: a single group.
Likewise with, for instance, the majority of voters – you may say The majority of voters decides the vote, because it is the fact of a majority that is decisive, but it is only (and not always) in newspapers and similar places where a writer is striving to be correct but doesn’t fully understand the grammar that you will see The majority of voters doesn’t want this rather than don’t want this.
So, since I have already said that a couple here is equivalent to “two”, “roughly two”, or “a few”, you would expect that it should be There are a couple rather than There’s a couple, right? And in fact in formal standard English that is so, because in formal standard English we match the number in there is/there are to the number of the predicate. But in casual English we often don’t do so, and it’s not because we’re ignorant or illiterate – it’s because it’s an arbitrary decision.
There is is really just an existential predicate, and there’s nothing other than convention that forces us to match it to the object. Spanish and other languages that use a version of “have” rather than “is” don’t do it (Hay dos cervezas sobre la mesa; Il y a deux bières sur la table); German doesn’t do it with its “give” verb (Es gibt zwei Biere auf dem Tisch); even some languages that use a version of “is” don’t do it (Tá dhá beoir ar an mbord – Irish).
Remember that what comes after there is is structurally the object. In normal usage (in English), objects have no effect on the number or person of the verb – it matches the subject. We don’t normally force the copular verb to match its object, even when adhering to the nominative object “rule”: not It am I but It is I, and not It are we but It is we… which, of course, normal people say as It is us, even when the It is empty. The famous quote from Pogo (appropriate with respect to grammatical confusion and disputes) is “We have met the enemy and he is us,” not “he are us.”
It’s just because the there in there is is just a placeholder, and not even a noun or pronoun, that we have the habit of matching the number of the verb to the object – the object is the only noun in the area, so we conclude that it must be the subject. There is also a mistaken belief that There is a person is an inversion of A person is there; this is not true – there is no spatial reference in there is. When we use there to point to a location, we have to have a location to point to, either present in context or established in text. If I say There is a mistaken belief, there is no “there” there.
In some languages, a subject isn’t even supplied for existential predicates; there’s just a verb. English doesn’t like bare verbs, so we always put something – there or it – in the subject position. Which works fine until someone stops and says “What is it? Where is there?” It gets to be like a person who starts analyzing the muscle movements in walking and finds he/she can’t remember how to simply walk anymore.
Thus, the use of there are rather than there is with plural predicates is learned behaviour, and is not truly natural – as witness the fact that even highly literate people often use the singular in casual use or unguarded moments. That doesn’t make it correct in formal English, but it does explain a couple things about it.