linguistics1-7  Exercise 1: Classifying Speech Acts
===================================================

  (a) I promise to call you tomorrow    COMMISSIVE (it commits the speaker); it is
                                        also a performative, since saying it
                                        makes the promise.
  (b) Could you open the window?        DIRECTIVE (it tries to get the hearer to
                                        act), here as an indirect one in the
                                        form of a question.
  (c) I'm so sorry                      EXPRESSIVE (it expresses a feeling).
  (d) You're fired                      DECLARATION (saying it changes the
                                        situation, provided the speaker has the
                                        authority to do it).
  (e) It's raining                      ASSERTIVE (it states how things are).

Why "Yes" is an odd reply to "Can you pass the salt?"

  The sentence has the form of a question about the hearer's ability, but
  its purpose is a request. A hearer who answers "Yes" has understood the
  form and ignored the act. The reply is not wrong as a statement (it is
  true), but it fails pragmatically, because it does not respond to what the
  speaker meant. Native speakers hear the request automatically; it is one
  of the many things you only notice when it fails.