Final answer:
The pronouns 'who' and 'whoever' are subjective case pronouns, used as subjects in a sentence. Conversely, 'whom' and 'whomever' are objective case pronouns, used as the object of a verb or preposition.
Step-by-step explanation:
The student's question seems to include a common mistake in pronoun case usage. The pronouns 'who' and 'whoever' are actually in the subjective (or nominative) case, meaning they are used as the subject of sentences. For example in the sentence 'Who wants ice cream?', 'Who' represents the subject of the sentence.
On the other hand, 'whom' and 'whomever' are used in the objective case, meaning they can be the object of a verb or preposition. For example: 'To whom was the letter written?', 'whom' is the object of the preposition 'to'.
You can easily remember this by relating 'm' in 'whom' to 'm' in 'him', both of which are objective case pronouns.
Lastly, objects in compound structures use objective case pronouns as well. For instance, 'Occasional disagreements about the dishes come up between Antonio and me' where 'me' is an objective case pronoun.
Learn more about Pronoun Case