1. The sentence that contains a pronoun that is not in the proper case is A) The principal decided that the ultimate decision about dress code should be left to we students.
<u>The pronoun that is not in the proper case is "we", which is a subject pronoun</u>, that is to say a pronoun that replaces a noun as subject of a sentence. The use of "we" in this sentence is incorrect and<u> it should be replaced with the pronoun "our", which is a possesive pronoun</u>. In this case, "our" should be used to indicate that the students, which is the noun that comes after the pronoun, belong to that specific school.
2. The sentence that has a possesive noun error is A) The management believed it had little choice but to lay off the companies highest paid employees.
<u>The mistake in this sentence is "companies"</u>.<u> "Companies" must be changed to "company's"</u> because the sentence is making reference to the management of one company and not more than one. Moreover, the possesive noun or genitive case ('s) is used to show possession or to show that someone belongs to a group. In this case, <u>the genitive case must be added to indicate that the "highest paid employees" belong to that company. </u>
3. The sentence that has an error is C) At the beach with her two sisters, John's mother wasn't sure whether those flip-flops were hers' or one of theirs.
<u>The error that this sentence has is "hers'"</u>. Hers is a possessive pronoun; therefore, it is used to indicate possession. In this case, it is used to signal that John mother might possess those flip-flops. However, <u>the mistake is in the apostrophe (')</u>. <u>The apostrophe should not be added at the end of the word</u>. In general, apostrophes are not added at the end of possessive pronouns.
4. The possessive pronoun that best completes the sentence is B) their.
<u>The possessive pronoun "their" indicates that two or more people possess something</u>. In this case, it is used to show that both Mr. and Mrs. Rhodes own a car. In that way, option a) is incorrect because "the" is an article and not a possessive pronoun, while d) is also incorrect because "they" is a subject pronoun. Moreover, it is not possible to use the possessive pronoun "theirs" as option c) suggests because the pronoun in the sentence is followed by a noun. In contrast to "theirs"<u>, "their" can be followed by a noun</u>. Therefore, option b) is the correct one.