[…] many morpheme classes (or, in some cases, sub-classes) have a common class meaning. In many languages we find that the distributionally determined classes (of morphemes, or morpheme sequences) have meanings which we may roughly identify as ‘noun’, ‘verb’, ‘preposition’, etc. Even classes of morpheme classes may have vague meaning characteristics. For example, in many languages the free morphemes (of whatever class) may be said to indicate objects, actions, situations, and the like, while the short bound morphemes (again of whatever class) indicate relations among these, times and persons involved, and the like.
- Harris (1951), a pag.252, n.21