Substitives and suffixes

Recently I returned from taking a three-week JHU summer program.  The
class I took was on etymologies, and it also covered a lot of basic
linguistics.  I learned quite a bit.

During the course, I realized that English has many ways of forming
new words.  Two of these are substitive words, where a word is used as
another part of speech (i.e. American for an American PERSON; noun
becomes an adjective)  and the process of adding suffixes to change
the part of speech (for example teacher from teach + -ER).

What I want to know is whether these two processes are standard in
other natlangs as well.  I speak a little French, but not enough to
know.  I specifically am wondering about non-IE langs such as
Japanese.

Eviendadïl, my conlang, has a few suffixes, but not many, and no pure
substitive words.  If however, these processes are normal in all
natlangs, it would allow me to add them.

Saránïl edórir,
Matthew Kehrt
Certê-ä "Matthew William" sa Mathyü Üilyám
--
Saráth evenü, cán el-sayü liné!