There are some old fossils around – not me, of course – who listen to radio and TV these days and fume and huff and puff at the malapropisms and linguistic gaffes of the so-called modern literati: the impossibly young presenters who do not so much string sentences together as throw words at the firmament and hope that they coalesce in the brains of their audience as the user intended them to be understood.
I’m The audience is too busy growling.
One usage that has seemed to me to have grown more and more common, arriving unbidden in the midden of American television shows is the construction “so fun! ”
Grammatically speaking, what we’re being asked to accept here is the ability to take a noun – fun – and somehow intensify it by using so. Sorry, it can’t be done.
So can function as an adverb, an adjective, or a conjunction. In order to modify a noun like fun it would have to behave as an adjective. The problem with that is that in order to behave as an adjective, so must be given a value of some sort: much, very, quite, just, and so on. Without that value, the word functions as an adverb and as such cannot modify a noun.
The rules around this are basic grammar and tinkering with them threatens the fabric of reality. Well, no, not really, but it does kind of disrupt the basic underpinnings of the language. So, the best we can say about this construction is that it is most unlikely to become formalised because it can’t become regularised. As an informal usage, however, it does have a certain charm when the footloose and fancy free young use it.
We The old farts just don’t like it shifting into the mouths of formal speakers who should know better. It patronises the young and confuses the old.
I’ll leave the last word to Paul Brians at Washington State University:SO FUN/SO MUCH FUN Strictly a young person’s usage: “That party was so fun!” If you don’t want to be perceived as a gum-chewing airhead, say “so much fun.”