[…] if we were to use different signs for all the shades of case-relation which we can recognize by analysis in our speech, we should have to multiply our list of prepositions many times.
- Whitney (1875), a pag.217

Prepositions, in our sense of the term, are of […] recent origin, created a separate part of speech by the swinging away of certain adverbs from apprehended relation to the verb, and their connection in idea with noun-cases which their addition to the verb had caused to be construed with it.
- Whitney (1875), a pag.208-209