Identify the error in the sentence: The team are preparing for the championship.

The sentence "The team are preparing for the championship" contains an issue with subject-verb agreement. In American English, collective nouns such as "team" are typically treated as singular when they refer to the group as a single entity. Therefore, the correct form should use a singular verb: "The team is preparing for the championship." This ensures that the singular subject "team" agrees with the singular verb "is." Understanding how collective nouns function is crucial for maintaining grammatical accuracy in writing.