Nigger is used as both a racial slur and term of endearment. Demonstrates how the same word can have an antipodal meaning.
EDIT: Per requests, below is a fuller elaboration of the above.
this is to promote the idea of the aspect of competently communicating one's ideas.
Words are symbols that reflect an idea. When we communicate with another person, one assumption we are making is that our words map to the same, or at the very least, a similar idea.
Problems emerge when the idea we are trying to convey with a particular word has different meaning to our recipient. The importance of this is that in order to communicate competently, we need to appreciate that it takes more than just words in order to "speak the same language".
I think nigger is a good example of this, with the N-word and nigga reflecting our peculiar attempts to navigate this treacherous terrain.
By way of example, we consider the following scene from the comedy film 40 Year Old Virgin (2005).
Here, two African-American men get into an argument. At first, nigger is used endearingly, but interpreted to mean servitude. Matters quickly escalate:
Customer: Now don't be a negro, be my nigga. aight, help me out.
Jay: Woah woah woah hold on, I ain't nobody's nigga.
Customer: Well, I mean you's somebody's nigga, wearing this nigga tie.
Jay: Now you're being condescending. See you've been warned aight. Just move forward amicably.
[Further antagonism by customer]
Jay: Okay see, see now you found yourself a nigga. You was looking for a nigga, Nigga here now!
In the following, we note attempts to reconcile these two contrasting meanings by attempting to delineate nigga from nigger.
Disagreement about the appropriateness of this resulted in the suspension of a high school teacher. The image below is a satirisation of the event in an episode of the animated comedy Boondocks
The original news report may be viewed here and is recommended. I find it both hilarious and interesting:
Lethality of misuse
Would misuse of nigger lead to actual bodily harm or death? Although it's possible, it's highly unlikely. However, I firmly believe that its inappropriate use can effectively lead to a type of social death.
One example of this is the end of the stand-up comedy career of Michael Richards, who played the character Kramer in the TV comedy series Seinfeld after he used nigger in a comedy routine.