Steven Pinker - a linguist, a cognitive theorist, and not least of all a psychologist - brought us
How the Mind Works which many of you, no doubt, enjoyed. Now he waxes on about our dirty tongues in
What the fuck? Snippet:
If the fucking in fucking brilliant is to be assigned a traditional part of speech, it would be adverb, because it modifies an adjective and only adverbs can do that, as in truly bad, very nice, and really big. Yet "adverb" is the one grammatical category that Ose forgot to include in his list! As it happens, most expletives aren't genuine adverbs, either. One study notes that, while you can say That's too fucking bad, you can't say That's too very bad. Also, as linguist Geoffrey Nunberg pointed out, while you can imagine the dialogue How brilliant was it? Very, you would never hear the dialogue How brilliant was it? Fucking.
Please note that I have not used my normal style of quoting, which employs italics, because there was so much use of italics in the actual article.