In the sentence "During the blackout, one of the patients were frightened and screamed loudly," which word is incorrect?

In the sentence, "During the blackout, one of the patients were frightened and screamed loudly," the word "were" is incorrect due to subject-verb agreement. The subject of the sentence is "one," which is singular. Therefore, it requires a singular verb form. The correct verb form that should be used with "one" is "was."

The sentence should read: "During the blackout, one of the patients was frightened and screamed loudly." This maintains proper subject-verb agreement, as "one" refers to a singular subject, even though "patients" is plural. Understanding subject-verb agreement is crucial for constructing grammatically correct sentences, and recognizing that phrases like "one of the" often lead to confusion is an important part of mastering grammar.