The only subtype of the large heterogeneous class of IPCs that has as yet been fully recognized as distinct within recent work is the subclass of interjections. Interjections (IPJ) are a special class of words, often quite short, which typically stand alone outside the usual syntax of the clause or sentence. They can be and have been classified simpoly as IPCs, but are distinct syntactically.

One type of interjection is the expressive, which typically serves to vocalize a speaker’s feelings, without necessarily being meant to convey meaning to an addressee. Examples of expressive interjections include the following which express pain (1), fear (2), surprise (3), disgust (4), anger (5), sadness (6), or joy (7), among other finer distinctions.

(1)  Pain:         awiyā        “ouch! ow!”

(2)  Fear:         īh              “eeek! yikes!”

(3)  Surprise:   wahwā      “oh my! wow! good gracious!”

(4)  Disgust:     cah           “geez”

(5)  Anger:       āh             “ah! oh! och! well!”

(6)  Sadness    āmī           “oh my!, oh dear!”

(7)  Joy:            yahē         “yesss!”

Many other interjections serve as “holophrases” or single-word utterances to represent complex interactions between a speaker and addressee. Such interactive interjections can include, but are not limited to, greetings (8) – both opening (8a) and response (8b), – partings (9), asking (10), thanking (11), acknowledgement (12), agreement (13), disagreement (14), directives (15), and warnings (16).

(8)  Greetings:
  a)   Opening:                     tānisi             “hello, how are you?”
  b)   Response:                   ēýiwēhk         “as well as may be, better than nothing; so-so”

(9)   Parting:                      mwēstas        “later, see you later!”

(10) Asking:                      āh                   “eh? what? what’s that?”

(11) Thanking:                  hay hay          “thank you, thanks”

(12) Acknowledgement:    kah                 “oh! yes, I see!”

(13) Agreement                 ēha                 “yes; agreed”

(14) Disagreement:           mwāc              “no!, no way!, not so!”

(15) Directives:
  a)                                     awas               “go on! go away! away with you!”
  b)                                     āstam              “come, come here”
  c)                                     mah                “listen!, hark!; attention!”

(16) Warning:                   pēyāhtak          “be careful!, take it easy!”

There can, of course, be considerable overlap when particles are used both as interjections and as clausal constituents. For instance, tānisi can be used purely as a greeting, in which case it can be identified as an IPJ as in (8a), but it can also serve as an interrogative particle (IPC) when asking questions, as in (17).

(17)   tānisi ē-isiyihkāsoyan?
         “What is your name; How are you called?”

Similarly, the particle mwēstas (9) can be used alone as in interjection of parting, or as a temporal adverbial integrated within the sentence, as in (18).

(18)   “…, nanātohk nititācimonān ōma mwēstas ēkwa,” nititāw.
          ‘ “…, we were telling various stories afterwards,” I said to them.’ (Vandall & Douquette 1987:70-71)

(For further information on Interjections, see Syntax: Single-Word Utterances)