The Formation of Words

What are the ways a word can be formed? Not too surprisingly, the linguists have got this one covered. Let's see if I can't sum it up (with help from my old friend, Wikipedia):

Conversion, a sort of semantic extension where old words take on new meaning, is possibly the method by which the bulk of English words come into existence (take mistress).  Another obvious origin is the borrowing of loan words from other languages (naive).

There's also compounding, where several words are strung together (like mailbox); blending, where parts of words are joined (such as smog or sonar) agglutination, where prefixes, infixes, or suffixes are added (fearlessness); and back-formation (as in edit, from editor).

When onomatopoeic words are separated out, neologisms in modern-day English are relatively rare; that is, we very rarely speak in language that has not got some subtext, some history.  Interesting?  If we aren't using novel words, if everything we say is referring to something else, how much of what we think is unique?  And if our thoughts aren't original, what about our actions?

Or, then again, perhaps the productivity of language saves us from staleness after all.