Note 65 — V Form in Language: Grammatical Concepts
Reading edition
Footnote 65: Thus, the -er of farmer may he defined as indicating that particular substantive concept (object or thing) that serves as the habitual subject of the particular verb to which it is affixed. This relation of “subject” (a farmer farms) is inherent in and specific to the word; it does not exist for the sentence as a whole. In the same way the -ling of duckling defines a specific relation of attribution that concerns only the radical element, not the sentence.