I never understood the animosity directed by prescriptivists toward different than. For some reason there are pages with titles like “Never do this: ‘different than’“. Man, so if you’re willing to come down so harshly on a construction, you’ve got to have an air-tight argument against it, right? Well, not so much. The standard argument against different than is that different from makes a lot more sense by analogy to differs from (not *differs than). But that’s just plain silly.
First off, different isn’t derived from differ, as prescriptivists often imply, or even occasionally outright state. According to the Oxford English Dictionary, different comes from the Latin present participle of different-em, via French. Differ also comes from Latin, but from the verb differ-re. Now, in Latin, different-em was the present participle of differ-re, but that’s two languages removed from our own. So it’s simply sloppy research to claim/imply that different is derived from differ. Since they were different words when they arrived in English, there’s no reason why they need to use the same particle, from. And arguing that English grammar should be based on Latin grammar led to such idiotic edicts as “don’t split infinitives“, so don’t even try arguing that a Latin relationship is relevant here.
Alternately, it has been argued that because differs (from) and is different (from) are semantically equivalent, they must take the same preposition. But why would semantically equivalent phrases require the same preposition if they’re allowed to differ in the number of words and parts of speech they employ? And anyways, this isn’t the case for prefer and have a preference for:
(1a) I prefer candy to vitamins.
(1b) I have a preference for candy over vitamins.
In (1a), there must be no preposition between prefer and candy, while in (1b), there must be one (although it could probably be something other than for). Furthermore, there’re phrases similar to differ/is different that use other prepositions but have (at least approximate) truth-conditional equivalence:
(2a) His stuffed animal is dissimilar to mine.
(2b) His stuffed animal is not the same as mine.
So it doesn’t seem that semantic near-equivalence or similarity of form requires matching prepositions.
Finally, there’s the argument that than is “the conjunctive particle used after a comparative adjective or adverb” (OED, 1a), as in more than or grouchier than. Since different is not a comparative adjective, than can’t be used, the argument concludes. Ta da! Alas, this is only one function of than; you’ll note that it also follows certain non-comparatives: rather than, other than. Rather and other instead set up an opposition between two objects or sets. This, to my mind, is similar to what different does.
So what’s the big deal here? There’s no reason to mandate from on an analogy to differ. (By the way, that’s not the way analogy normally works in linguistics. Analogy usually is used to explain a novel form, such as the regularization of a verbal paradigm, not to justify the incorrectness of an existing form.) And than‘s not a bad fit here. Plus, different than has a usage that different from just can’t do:
(3a) The texture of fried jellyfish was different than/*from I’d expected.
(3b) The texture of fried jellyfish was different than/from what I’d expected.
(If you’re interested in more in-depth information about the status and usage of the different different prepositions, check out pages 341-343 of Merriam-Webster’s Dictionary to English Usage.) So let’s stop deriding different than; it’s valid, it’s useful, and it’s natural.
Summary: The arguments against different than just don’t hold water. Different isn’t derived from differ, so it doesn’t require from by that argument. Semantically similar phrases don’t require the same prepositions, so that argument falls as well. And than is used in other non-comparative contexts, so it’s a reasonable particle to use there. So go ahead and use different than if you feel like it sounds better.