Some Non-Productive Affixes
-ly, -some, -en, -ous
Note. The native noun-forming suffixes -dom and -ship ceased to be productive centuries ago. Yet, Professor I. V. Arnold in The English Word gives some examples of comparatively new formations with the suffix -dom: boredom, serfdom, slavedom . The same is true about -ship (e. g. salesmanship). The adjective-forming -ish, which leaves no doubt as to its productivity nowadays, has comparatively recently regained it, after having been non-productive for many centuries.
Semantics of Affixes
The morpheme, and therefore affix, which is a type of morpheme, is generally defined as the smallest indivisible component of the word possessing a meaning of its own. Meanings of affixes are specific and considerably differ from those of root morphemes. Affixes have widely generalised meanings and refer the concept conveyed by the whole word to a certain category, which is vast and all-embracing. So, the noun-forming suffix -er could be roughly defined as designating persons from the object of their occupation or labour (painter — the one who paints) or from their place of origin or abode (southerner — the one living in the South). The adjective-forming suffix -ful has the meaning of "full of", "characterised by" (beautiful, careful) whereas -ish may often imply insufficiency of quality (greenish — green, but not quite; youngish — not quite young but looking it).
Such examples might lead one to the somewhat hasty conclusion that the meaning of a derived word is always