General Rule:
* Periods always go inside quotation marks in American English.
Exceptions:
* When a quotation is part of a larger sentence and the period is part of the larger sentence, the period goes outside the quotation marks.
Examples:
Inside the Quotes:
* "The quick brown fox jumps over the lazy dog."
* "I can't believe he said, 'I'm the best.'"
* She said, "I'm going to the store."
Outside the Quotes:
* Did you hear her say, "I'm going to the store"?
* The article was titled "The Future of AI."
* He asked, "What time is it?" but nobody answered.
Key Points:
* Focus on the overall sentence structure. If the quotation is a complete sentence on its own, the period goes inside. If the quotation is part of a larger sentence, the period goes outside.
* **The "Chicago Manual of Style" (CMS) is a widely respected guide for writers and editors. They use a system where periods *always* go inside quotation marks, even in cases where a larger sentence structure might suggest otherwise. This is common in academic writing.
* For academic or professional writing, consult the style guide specific to your field or organization to ensure you are using the correct punctuation style.
Let me know if you'd like more examples or have any other grammar questions!