Which word in the sentence should be capitalized: 'My aunt Jean asked the professor, "How will we get to Sunnyfield stadium given the construction road block on the west side of Cherry Street?"'?

In the sentence, capitalizing "Sunnyfield" is crucial because it is part of a proper noun—the name of a specific location, the stadium. Proper nouns, which name specific people, places, or organizations, are always capitalized in English writing.

The term "stadium" by itself is a common noun. It does not refer to a specific entity on its own in this context and therefore does not require capitalization unless it is part of a proper noun. Other words in the sentence, such as "aunt," "professor," and "west," do not meet the criteria for capitalization in this context; "aunt" is a familial relationship and "professor" is a title that does not need to be capitalized unless used with a specific name, and "west" is only capitalized when it is part of a proper noun, such as "West Cherry Street." Thus, identifying the need to capitalize "Sunnyfield" as a part of "Sunnyfield stadium" is essential for proper grammar.