The element 'b' ('-s', '-ing', '-er') is the indicator of a subsidiary and, as a rule, a more abstract concept; in the widest sense of the word 'form', it puts upon the fundamental concept a formal limitation.
- Sapir (1921), a pag.26

Nothing could be more erroneous than to imagine that symbolic changes of the radical element, even for the expression of such abstract concepts as those of number and tense, is always associated with the syntactic peculiarities of an inflective language.
- Sapir (1921), a pag.131