Final answer:
The incorrectly capitalized word in the sentence is 'i'. It should be capitalized to 'I' even when included in a compound subject, aligning with standard English grammar rules.
Step-by-step explanation:
The word in the sentence 'You and i are very good friends.' that is incorrectly capitalized is 'i'. The correct sentence should be 'You and I are very good friends.' The pronoun 'I' should always be capitalized, regardless of its place in a sentence.
This is a rule that applies even when 'I' is part of a compound subject, as in the sentence provided. To contrast, 'me' is always used as an object, and its capitalization doesn't change.
It's important to remember the pairing of subjective case pronouns with compound subjects, and the objective case pronouns with compound objects.
For example, the correct construction using the subjective case is 'Antonio and I have occasional disagreements about the dishes', while the objective case would be 'Occasional disagreements about the dishes come up between Antonio and me'.