Question

Which sentence has a subject-verb agreement error? A) A man in a strange cloak and hat is walking on our back porch tonight! B) One of my sister's friends that she made in her college sorority are a doctor. C) The politicians who had supported the disastrous policies apologized profusely. D) The villagers who were sick with dysentery were cared for by the local Jesuit priests.

Answer 1

The answer would be B) One of my sister's friends that she made in her college sorority are a doctor.

The subject-verb error occurs in the words made and are. Made indicates a past-tense event, while are indicates the present-tense. To fix the sentence, you could change are to is. 

One of my sister's friends that she made in her college sorority is a doctor.

Answer 2

Answer:

The answer to your question would be that the sentence that has a subject-verb agreement error is the following one: One of my sister's friends that she made in her college sorority are a doctor. That is, the correct option would be A.

Explanation:

This sentence contains a subject-verb agreement mistake. In order to identify the error, you should first identify the subject of the sentence. The subject of the sentence above is the NP "one of my sister's friends that she made in her college sorority". The head of the noun phrase is one. Therefore, the verb should agree with this noun yet the verb is plural (are a doctor). The fact is that the subject and the verb must agree in number, that is, both need to be singular or both need to be plural.

Revised version of the sentence: One of my sister's friends that she made in her college sorority is a doctor.