Here's why:
* Word Root: A word root is the core meaning of a word. It's usually a Greek or Latin term, and by itself, it often doesn't make sense. For example, "graph" means "write".
* Combining Form: A combining form is a word root that is modified so it can be joined with other words to create new words. It often involves adding a vowel (usually "o" or "i") to the word root. For example, "graph" becomes "graph-o-" or "graph-i-".
* "Plus": "Plus" doesn't have any specific linguistic meaning in this context.
Here's a better way to understand combining forms:
Think of combining forms as "building blocks" for new words. They add meaning to a base word or another combining form. For instance:
* "Graph" + "y" = "graphy" (writing, as in "photography")
* "Graph" + "o-" + "meter" = "graphometer" (a device for measuring)
So, a combining form is a modified word root that can be used to combine with other words, not just a word root "plus" something else.