The phrase "the promises of some calves" includes one possessive noun ("calves'" if it were modified) and a plural noun ("calves"). To clarify:
- Possessive noun: If we were to make "calves" possessive, it would be "calves'" (indicating that something belongs to the calves).
- Plural noun: "calves" is already plural referring to more than one calf.
If you want a sentence with both in a more structured way, you could say:
"The calves' promises for the future were surprising."
Here, "calves'" is the possessive noun, and "promises" is plural referring to multiple instances of a promise.