In my book about grammar geekery I was writing some dialog, and stumbled on the material for another whole chapter. It's a perfect example of where the good practice of descriptive grammar creates controversy where there should be none, and comes from the desire (erroneous I think) to classify "than" as one of the two common invariant particle types: preposition or conjunction. Swift loved this sort of thing.
If you view "than" as a conjunction, then it should be found between two grammatically complete clauses.
If you view "than" as a preposition, then it should take an accusative compliment (an object noun or pronoun), "like it does in Latin".
But Latin is far too sensible for silliness over "than". Quam is technically an adverb, modifying the verb into a comparison with itself. Tarquin is prouder than Horatio >> Tarquinius superbior quam Horatium
est >> implies that quam est means "is compared with" >> Tarquin is more proud compared with Horatio.
Sadly, English is not Latin.
The conjunctionists and the prepositionists (for which read bigendians and littleendians) both come up with some clever arguments for why it should be theirs, and according to which side you are on, you would follow than with either a subject or an object:
Noone hates implied clauses more than I.
Noone hates implied clauses more than me.
The former provides me with a rare (but perfect) opportunity to use the word "specious". The argument claiming that it is a conjunction states that "than I" is short for the implied second sentence "than I hate implied clauses." It doesn't take a genius to see what's amiss here. We don't normally say:
She loves you more than I love you.
What we do say is:
She loves you more than I do
and we say that when we want to avoid the possible ambiguity of:
She loves you more than me
which might mean:
She loves you more than she loves me.
Of course, the only time that it is ambiguous is when the context doesn't indicate who ought to be loving whom, and such situations, I suggest, are fairly uncommon.
I observe in modern English that, like in Latin, we do not say "Tarquin is more proud than Horatio is proud, but "Tarquin is prouder than Horatio."
To push it a bit further, here's another Latin example:
Is vidit paucos servitos fideliores quam eum.
For clarity's sake, we would typically translate with: "he has seen few servants more loyal than this one".
Who really thinks that this is an abbreviation of "he has seen few servants more loyal than this one is loyal" ?
Than is neither conjunction nor preposition. It is an indicator of comparison; the sentence is structured around the pairing of "more" with "than", just as in the earlier example, "prouder" and "than" are paired to explain a comparison.
It isn't a conjunction because although without it you get grammatically complete sentences, you don't get meaningful ones and further more, by inserting it, part of one of the sentences becomes redundant – this does not happen with conjunctions.
He has seen few servants more loyal. This one is loyal.
It isn't a preposition because it isn't indicating a relationship. I found myself wondering about relativity.
Consider Alice and Bob, in the vacuum of interstellar space. Let us provide them with spacesuits and an adequate supply of oxygen.
Alice is facing Bob.
This is an expression of relativity. It gives Alice's position relative to Bob, but to nothing else in the Universe. That makes it pretty relative.
Alice and Bob are side-by-side.
Philosophically, this is the same kind of statement, though diagram it and you get something different.
Alice is taller than Bob.
Something is different, here, and it is that there is a difference being expressed. Alice is singled-out for her height. In the other two sentences, we are essentially saying the same about both of them, so:
Alice is as worried as Bob about their air supply.
This can be constructed in the same way as a sentence with "than":
Alice is as worried about their air supply as Bob.
Now pretend this is a conjunction. If it is, we should be able to take away the conjunction and make two grammatically complete sentences if we complete the second one with the implied clause:
Alice is as worried about their air supply. Bob is worried about their air supply.
But as we are told, is an adverb, used in comparison, and it is the former as that is the operative one, so maybe I am being dense, but why can't than be an adverb?
Either way, these thought experiments are all very fascinating, but don't really help. As Wiktionary accurately observes:
prescriptionist rule [that it should be treated as a conjunction ] … is inconsistent with well-established usage
Against my usual convention, in researching I turned to the etymology last:
O.E. þan, conjunctive particle used after a comparative adjective or adverb, from þanne, þænne, þonne "then" (see then). Developed from the adverb then, and not distinguished from it in spelling until c.1700.
The earliest use is in West Germanic comparative forms, i.e. bigger than (cf. Du. dan, Ger. denn), which suggests a semantic development from the demonstrative sense of then: A is bigger than B, evolving from A is bigger, then ("after that") B. Or the word may trace to O.E. þonne "when, when as," such as "When as" B is big, A is more (so).
It is possible,
þen, þat it has a dual heritage, a parallel evolution from "þen" - then, and "þonne" - when (how I wish I had thorn on my keyboard). This would mean that, you would be a bigendian if you followed the descent from þen and a littleendian if you followed the descent from þonne. Probably, the twain shall meet, and it seems likely that they will meet on:
I hope you're smarter than me
I hope you're smarter than I am
I hope you're smarter than I.