In older books on language, the distinction between morphology and syntax is sometimes represented in terms of a distinction between "form" and "function". This also rests upon the implied primacy of the word: according to their "function" in the sentence, which is accounted for by the rules of syntax [...], words are said to assume a different "form", and the different "forms" are handled by morphology.
- Lyons (2004), Pag. 14