What is exactly "descriptivism"?

Question

I think I understand that as a field, linguistics tries to study how people actually use language, rather than say how people should. It seems to me, a layperson, that several linguists writing for general audiences have argued quite persuasively that many prescribed rules are baseless. But I have some difficulty with a couple of issues:

1. Many people consistently say and write things that I think descriptivists and prescriptivists alike would call incorrect. And I don't believe these errors have anything to do with dialect. Just take the writing of the bottom of any typical high school English class, for example. Some errors like "There is many ..." I hear from people of all ages so frequently that I highly doubt such errors would qualify as "just slips," even in the descriptivist sense: if asked, the speakers wouldn't find any problem with them (I imagine).

2. Where's the line? Can we say that "if 30% (15%? 5%?) of the population accepts this usage, then we'll add it to our grammar of the language"? (Right about here I get the feeling in my stomach that someone will tell me that this is the wrong question.) And if the bar is sufficiently low, I think many rules I've seen categorized as prescriptivist nonsense will pass the test. Just a semester with a particular English teacher who insisted on such silly rules as "this must always be followed by a noun phrase; never write this is or this means" has made me extremely aware of violations of those rules. I have to pause for a moment whenever I hit upon a this explains in published news articles, and it's gotten really annoying. Surely generations of students of such indoctrination make up a sizeable readership? Sad as it is, this alone seems to be justification for the prescription.

Answer 1

Partially, it depends on how you think of what the goal of Linguistics is. I work within the Chomskyan paradigm, in which we think the goal of Linguistics is characterizing I-language. That is, we are interested in understanding how grammatical knowledge is represented in the mind. Unfortunately, this task will always require a certain level of idealization, because there is also some evidence to think that people will have subtle differences in their knowledge of their language, even if – from a bird's eye perspective – we say they both speak English. That is, language names (like English) are ultimately idealized theoretical fictions. The actual object of study is individuals' capacities.

That being said, reread your question. You mention that if you asked your students where "There is many.." is acceptable, they would say yes. That indicates that – since they both use it, and (presumably) find it acceptable – it is grammatical for them, not implying that it needs to be grammatical for anyone else. The question, then, of where we draw the line – at 15%, 30%, or whatever – is a legitimate question to ask, but it's a question about how to lump I-languages into the languages of a community, which, on the Chomskyan point of view, will always require certain kinds of arbitrary decisions to "iron out" the differences between I-languages.

That being said, if you don't imagine the object of study to be individuals' knowledge of their language, and disavow the mentalist perspective, your question is a very poignant one and difficult to address one.

Answer 2

As a linguist, when I go to work on a previously undescribed language I work with individuals to collect language samples then analyse these to make statements about the structure of the language. If one individual happily uses structures that no-one else in the community seems to use (and if I'm sure it isn't just performance error of some sort) then I'll ascribe that to the person's idiolect (individual variety). I might even mention this variation in my analysis though this would be more likely if there was a significant minority using it. I certainly wouldn't say that one variety is more 'correct' than the other. It could happen that this individual's usage will catch on and spread to become widely used in the community, or it may not.

While linguists talk about 'the grammar of the language' as though it's a single entity (it does make a handy book title) it's important to remember that each of us has our own grammar inside our head which enables us to produce linguistic utterances. For speakers of the same language much of this knowledge is shared, but that doesn't mean they're identical.

But it is also true that people produce utterances that are 'incorrect'. People make mistakes all the time and repair them if they notice, but they don't always notice. Geoff Pullum expands on this nicely. I suspect that at least some of the cases you've noticed of 'there is many…' might be mistakes, but some might not be.