Final answer:
The proper noun in the sentence 'You told Aunt Bess that your brother had won a special award for his research' is 'Aunt Bess.' This is because a proper noun refers to a specific name of a particular person, place, or thing.
Step-by-step explanation:
In the English subject, a proper noun is a specific name for a particular person, place, or thing. Proper nouns always begin with a capital letter. In the sentence 'You told Aunt Bess that your brother had won a special award for his research,' the proper noun is 'Aunt Bess.' This is because Aunt Bess is a specific person and her name is capitalized. Other parts of the sentence, although they refer to people or things ('brother', 'award', 'research') are not capitalized because they're not specific names; they're common nouns, not proper nouns.
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