According to Roman Jakobson in "Closing Statement: Linguistics and
Poetics" (1960), language has the following six functions:
referential: this is the most obvious function of
language, when you use words to indicate things or facts.
On E2, factual writeups use the referential function of language.
emotive: this is when you don't speak to convey an
information, but to express your feelings. Then you communicate for
yourself more than for the people who may (or may not) hear you.
On E2, Day Logs use this function almost exclusively.
conative: you try to make other people do
something. This includes orders and prayers.
The Everything University is a fine example of conative speaking. Node
What You Know!
phatic: this little-known function of language
consists in saying something only to maintain the contact with the person
you are speaking to. When you say "hello" on the phone or discuss about
the weather with your hairdresser, you are using the phatic function of
language. Your purpose is primarily to maintain the communication.
The all is quiet... message displayed in the Chatterbox when nobody
is speaking could be considered as a phatic message, because maybe the
Chatterbox would die if nobody said anything for too long...
metalingual: when language is used to speak about
language, for example in a grammar or a dictionary.
The nodes about language are metalingual. This node is metalingual. This
paragraph is metametalingual.
poetic: when the speaker focuses on the message for
its own sake. This functions encompasses more than poetry. For example,
euphony is an application of this function. You use the poetic function
of language when you say "Abbott and Costello" instead of "Costello and
Abbott", which has the same meaning. Georges Perec also used that
function whe he wrote La Disparition (A Void) without the letter e.
The poetic function has so many aspects that it is probably present
everywhere in E2. Even in nodes about poetry.
The theory behind that list establishes that saying something to someone
involves the following mechanism:
An Addresser sends a Message to an
Addressee.
The Message cannot be understood outside of a
Context.
The Addresser and the Addresse
need to understand the Code that explicits the
relationship between the Message and the
Context.
A physical Contact must be established between them
to convey the Message.
According to Jakobson, "each of these six features
(Addresser-Message-Context-Contact-Code-Addressee) determines a different
function of language." Which feature corresponds to each function is left
as an exercise to the reader. If my description of the function is not
too obscure, it should be easy.
Jakobson's essay is described at many places on the Internet. A good
place is http://www.chass.utoronto.ca/epc/srb/cyber/geo2.html