General Rules:
* Yes/No Answers: Typically, "yes" and "no" are capitalized when they stand alone as a complete sentence.
* Example: "Are you going to the party?" "Yes."
* Other Short Answers: If the answer is a single word other than "yes" or "no," it's usually lowercase unless it's the first word of the sentence or a proper noun.
* Example: "What's your favorite color?" "Blue."
Exceptions:
* Proper Nouns: Always capitalize proper nouns, even in short answers.
* Example: "Who wrote that book?" "Shakespeare."
* Starting a Sentence: If the short answer begins a sentence, capitalize the first word.
* Example: "Do you want to go?" "No, I'm tired."
* Emphasis: You might capitalize a word in a short answer for emphasis, but this is more informal.
Example:
"Is that your dog?"
"Yes, it is."
Key Takeaway: The main point is clarity. If you're unsure, err on the side of capitalizing. It's better to be slightly formal than to appear casual and incorrect.