Some authors use
Fictional languages as a device to underline differences in culture by having their characters communicate in a fashion which is both alien and dislocated. Primary examples of this are
George Orwell's
Newspeak in
1984, [Anthony Burgess]
?'s Nadsat
? in
A Clockwork Orange,, and
Ursula K. LeGuin's Pravic
? in
The Dispossessed. These languages are presented as distorted versions of modern English.
Others have developed fictional languages in detail for their own sake, for example the languages of JRR Tolkien's Middle Earth and Star Trek's Klingon?.