When is it rude to use this or that to refer to a person? A friend of mine, frustrated by someone who was moving too slow, muttered If this would only get out of the way…, and it was clearly a hostile putdown. But it's not a hostile putdown in a case like This person wants to know where the police station is. So could it be that when dependent this or that is used with a (non-insulting) noun denoting a human being it can be polite, but it's never polite to use it on its own to refer to a human being? No, that can't be right either, because it's perfectly polite to say This is my friend John. Whereas !*Have you met this? or !*This would like to meet you would be rude (I mark this grammatical-only-as-deliberately-rude status with a "!*" prefix). What is the rule or principle here? There must be one, because I know, tacitly, when to use this for human beings. It's just that I don't know what it is that I tacitly know.
I checked The Cambridge Grammar of the English Language (I know I'm a co-author, but the book always contains a bit more than I remember it containing, no matter what I'm looking up), and the topic is covered (pp. 1504-1506); but anyone looking for an insightful explanation would hardly be satisfied. Here's the best I think current linguistics can do:
- Dependent this and that (with a head noun) can be used with human-denoting head nouns to make reference to human beings: This man is my son.
- Independent this and that in the singular (without a head noun) constitute an exception, and cannot in general be used to refer to human beings: !*This seems to have broken his glasses; !*That who wants to earn more should work harder; !*If she's going out with that she must be desperate.
- Independent that in the plural (those) is an exception to the exception in that it can be used to refer to human beings: Those who want to earn more should work harder.
- But independent this in the plural (these) is an exception to the exception to the exception, because it cannot be used to refer to human beings: *These who want to earn more should work harder; !*These said they wanted to meet you.
- There is another exception to 2 regarding both independent this and independent that in the singular, in that they can be used to refer to human beings when they are subject of a specificational copular clause: This is my friend John.
- There is a third exception to 2 in the case of at least some ascriptive copular clauses with predicative complement NPs: That's a very tall man over there; This is a beautiful child you have here.
- There are (so far as is currently known) no other exceptions.
Why just those exceptions and no others? I have no idea. I am reduced to just listing the facts to be described. I have no idea whether all of the exceptions could be made to fall under some elegant general principle.
There may still be some linguists who think there are going to turn out to be simple and elegant principles governing all of English syntax and semantics, but I can't imagine which planet they're from. Here in the real world, it looks to me as if some parts of our language are just a messy and surprising chaos of partial patterns and exceptions to the patterns and exceptions to the exceptions. We shouldn't stop looking for elegant generalizations, but in my humble and privately held opinion we will sometimes find that they are just not there to be discovered. This looks like one of those times.
If there were any insights on how the above list could be recast to have more generalizations and fewer exceptions, I would want to know about it. I'm almost on the edge of thinking about leaving comments open… oh, what the heck.