Ah, I'm moving, so I haven't had time to, and have been too distracted to, write anything for all of you to . . . well, you know the name of the blog.
But look at this: Anu Garg is doing a whole week on prepostions! Closed class indeed.
He also says a few words about the rule against using those prepositions in a sentence-final sort of a way. I threatened to take up that subject myself not long ago, so I guess its time has come. I only have a few things to say:
First, an example that is a bit of a cheat ( taken from Garg's remarks): Which of these two sounds like something a human speaker of English would actually say: About what are you talking? or What are you talking about?
If the first sounds more natural to you, or even if you've ever uttered it in ordinary conversation, then this discussion has no value for you --it is not about the variety of English you speak. I don't worry about offending you because I don't think you exist. The rule would have to say something that no one would say. How can it be 'correct' if it's self-evidently awkward English?
I call this example a cheat because the preposition is stranded as a pretty much necessary part of forming the question: putting the question word standing for the object of the prepostion at the front of the sentence. But what about when the preposition is stranded in non-question sentences?
Those who forbid the sentence-final prepostion will have to explain why, in a sentence like "the accident gave him something to both apologize for and think about," the stranded preposition before the conjunction commits no offense to propriety, but the one before the period is outrageously unacceptable. What is different about the two positions in the sentence? One is at the end, but what is there at the end of the sentence that should make it a strictly segregated area forbidden to those second class (but very hard-working) sub-words, the prepositions?
Well, nothing, right? Just the rule --but ask the rule why it exists, or look into the sentence for some unwanted effect the rule exists to avoid, and there is nothing. The rule would have you say instead "the accident gave him both something for which to apologize and about which to think." Clearly an atrocity, and for no good reason --no reason at all, in fact.
I for one, insist on no atrocities without proper justification.