What is the copula in a proposition?

• A. The subject-term
• B. The form of the linking verb to be
• C. The predicate-term
• D. The logical form

Answer: (B)

The copula is the linking element that connects the subject-term to the predicate-term in a proposition. It is the form of the verb “to be” that expresses the relationship between the two terms, such as “is,” “are,” or their negative forms like “is not” or “are not.”

For example, in “All humans are mortal,” the word “are” is the copula; it links the subject-term “humans” with the predicate-term “mortal.” The subject-term and predicate-term themselves are the terms being connected, while the copula is the specific linking verb that shows how they relate. The overall logical form of a proposition includes more than just this link (it also involves quantity and quality), so the copula is distinct from the complete form.

That’s why the other elements aren’t the copula: the subject-term is the topic of the proposition, the predicate-term is what’s asserted about the subject, and the logical form is the entire proposition structure. The copula specifically is the form of the linking verb.