Negation

[Porter]

Are there any general rules for negating a word in English?  I wrote non-audible today, and only later realized that the correct form should be inaudible.  Why is it inaudible instead of unaudible?  I have no idea.

[Jonathon]

Generally speaking, un- goes with English words, and in- goes with Latin words. There's a lot of overlap, though, probably because most people don't keep track of the origins of the words they use. have And then there's a-/an- which goes with Greek words, but there are a lot fewer of those in English. These prefixes usually give a word the opposite meaning, while non- usually implies simple negation. I'm sure there are logical terms that are used to differentiate these senses, but I've forgotten them.

[Porter]

Generally speaking, un- goes with English words, and in- goes with Latin words.

Ugh.  That's not terribly helpful because

most people don't keep track of the origins of the words they use.

Oh well, thanks.  It's not like I really expected there to be a reasonable answer.

These prefixes usually give a word the opposite meaning, while non- usually implies simple negation.

Inaudible being a convenient exception.

[Jonathon]

Yeah, sorry. There really aren't any simple guidelines unless you can easily spot a word's language of origin, and even then it's a mess, like with unjust and injustice. I'd say if you're not sure whether it should be in-/un- or non-, try one or both of the former first and see how that sounds.  

[Tante Shvester]

I know that in medical jargon, we use a- and an- lots.  I guess because of the Greek thing.  I always figured that it was to make the jargon more obscure to the uninitiated.

Ooh!  Uninitiated!  That's like a double-negative itiated!

[Jonathon]

Sometimes in- just means in.

[Porter]

Doubleplusungood.

[Tante Shvester]

So, "untoward" would mean "adverse", but "intoward" would mean that you like Wally and Beaver's dad.  Got it.