Identify the grammatical function of the bolded noun clause in this sentence:

Will's problem was that he didn't know how to register for classes.

A) subject

B) direct object

C) predicate nominative

D) object of a preposition

The correct answer is C: predicate nominative.

Explanation:

Will's problem was that he didn't know how to register for classes.

Predicate nominative represents a group of words that completes a linking verb and renames the subject. A predicate nominative can be found after a linking verb.

In our example, the subject would be Will's problem, the linking verb would be was, while the rest of the sentence would represent a predicate nominative.