I will discuss the extreme power we have to change a word's entire meaning by How the word is used and perceived. An example of this is slang. I also find that words have an extreme effect on our emotions. Like when we here a song and the lyrics are put together in such a way that if the words themselves were to stand alone then they would have no effect at all. There are some feelings or emotions that we experience that there simply no words for.
Words can never convey the sharpness of an experience after the fact.
Also words are not always good in some cases. For example when one first meets and attraction one does not come out and say that they are attracted to the other but rather use the nonverbal communication.