Identify the error: One of the boy has broken the window.

The error in the sentence "One of the boy has broken the window" is in the phrase the boy. The correct answer is the boy. This question tests the grammatical rule concerning the phrase "one of the." When using "one of the," it must always be followed by a plural noun. This is because you are referring to one item or person selected from a group of multiple items or people. Therefore, "boy" should be "boys." The correct construction would be "One of the boys has broken the window." The verb "has broken" is correct because the true subject of the sentence is "one" (singular), not "boys." If the subject were plural, the verb would also need to be plural (e.g., "Many of the boys have broken the window"). Understanding this specific grammatical structure is crucial for accurate subject-verb agreement and noun usage.