I. Three Basic Functions are generally noted: there is perhaps nothing more subtle than language is, and nothing has as many different uses.
A. Without a doubt, identifying just these three basic functions is an oversimplification, but an awareness of these functions is a good introduction to the complexity of language.
B. The Functions of Language (i.e., its purpose; what it does; its uses)
1. Informative language function: essentially, the communication of information.
a. The informative function affirms or denies propositions, as in science or the statement of a fact.
b. This function is used to describe the world or reason about it (e.g.., whether a state of affairs has occurred or not or what might have led to it).
c. These sentences have a truth value; that is, the sentences are either true or false (recognizing, of course, that we might not know what that truth value is).  Hence, they are important for logic.
2. Expressive language function: reports feelings or attitudes of the writer (or speaker), or of the subject, or evokes feelings in the reader (or listener).
a. Poetry and literature are among the best examples, but much of, perhaps most of, ordinary language discourse is the expression of emotions, feelings or attitudes.
b. Two main aspects of this function are generally noted: (1) evoking certain feelings and (2) expressing feelings.
c. Expressive discourse, qua expressive discourse, is best regarded as neither true or false. E.g., Shakespeare’s King Lear’s lament, “Ripeness is all!” or Dickens’ “It was the best of times, it was the worst of times; it was the age of wisdom; it was the age of foolishness…” Even so, the “logic” of “fictional statements” is an interesting area of inquiry.
3. Directive language function: language used for the purpose of causing (or preventing) overt action.
a. The directive function is most commonly found in commands and requests.
b. Directive language is not normally considered true or false (although various logics of commands have been developed).
c. Example of this function: “Close the windows.”  The sentence “You’re smoking in a nonsmoking area,”  although declarative, can be used to mean “Do not smoke in this area.”



Philosophy 103: Introduction to Logic Common Forms and Functions of Language