"Interjection" comes from the Latin words for "throw" ("ject") and "among" ("inter"). An interjection is thus a word or construction that is "thrown among" the words in a sentence. In speaking, short interjections are common, but ........
I don't suppose SLPs would ever teach Interjections, but since they are considered one of the eight basic parts of language, they are included here. There is not much information about them on the web, except for descriptions of what they are. From the paucity of web sites that deal with them, it is clear they are not important to teach.
Interjections: are words or phrases used to exclaim or protest or command. They sometimes stand by themselves, but they are often contained within larger structures.
Some of the more common interjections and the meanings they communicate are shown in a table at the following web site: http://www.englishclub.net/grammar/interjections/interjections.shtml An additional web site that simply lists the more common interjections can be found at http://teenwriting.about.com/library/blextras/blextra374.htm?terms=interjections
Common interjections are: Ah, Alas,Darn, Dear, Eh, Er, Hello, Help, Hey, Hi, Hmm, Oh, Oops, Ouch, Stop, Uh, Uh-huh, Well, Wow.
The meanings they express are typically emotional, such as: surprise, pleasure, realization, resignation, pity, grief, repetition, inquiry, agreement, attention, pain, hesitation, etc.
http://www.dcsd.k12.nv.us/class/tuggle/interjections.htm This is a very cute way to teach interjections. Its a story that you can use and ask for participation from your students. Good for elementary level children.
http://www.aitech.ac.jp/~iteslj/quizzes/9807/mn-interjections.html Fifteen multiple choice questions testing the correct use of interjections. This site emphasizes using specific interjections in environmentally appropriate situations. It also emphasizes using specific interjections to communicate certain emotions.
http://www.lessontutor.com/eesinterjection.html Here is a lesson plan. The plan explains what interjections are and at the end of the plan is an exercise. Eight questions are presented and the student's task is to simply IDENTIFY the interjection. Very easy task.
http://www.stufun.com/exercise/interjections_1.pdf Five opportunities to respond here. Have your students fill in an appropriate interjection at the beginning of each sentence. You might want to have a group of interjections available for them to choose from.
http://www.le.ac.uk/ee/jmc21/legp/interj1a.html At this site students have five opportunities to pick out the interjections from multiple choice sets.
http://teenwriting.about.com/library/writinglessons/blpartsofspeech10_2.htm?terms=interjections If you scroll all the way down to the bottom of this site you'll find a Treasure Hunt game. It is suitable for junior high and high school students. It's similar to a Hangman game, but you get no clues. All the answers are interjections, but there are some weird ones. I would suggest you try the game in advance. You can just click on the "solve button" and get all the answers. That way you could make the task easier by giving your students some clues ahead of time.