Wow!  But!  Ouch!  Duh!

Information

What is an INTERJECTION?
    Expresses emotion.

    Has no grammatical relation to any words in the sentence.

    From the Latin inter, meaning between and jactus,
  
       meaning thrown.  Loosely means thrown between.

     Interjections are short exclamations like Oh!, Hey! or Ouch!

     Interjections are sometimes followed by an exclamation mark (!) or comma (,) when written.

    A sentence can stand alone and make sense without the interjection.

    Some words are only used as interjections.  Examples:  ouch, oh, whew, psst, or tsk-tsk.  

    Interjections can be another part of speech.  Examples:  great or baloney.

    Interjections can be one word statements or questions.   Examples:  Yes, No, Right?, or Ready?

    Only used as part of the subject or predicate, when used in a quotation.

    Are normally used in spoken language rather than written.