When it's okay:
* Direct Quotation: You're introducing a direct quote from someone else. This is the most common reason.
* Example: "I have a dream," Martin Luther King Jr. famously said.
* Dialogue: You're writing a story or dialogue and starting a character's speech.
* Example: "Don't go near the water," she warned.
* Title of a Work: You're referring to the title of a book, song, movie, etc., especially if it's a short title.
* Example: "The Great Gatsby" is a classic American novel.
When it's not okay:
* Incorrect Usage: Don't use quotation marks to highlight a word or phrase unless it's a direct quote.
* Incorrect: "This is a great idea."
* Correct: This is a great idea.
Important Considerations:
* Punctuation: The punctuation of a sentence that begins with a quotation mark depends on the entire sentence structure.
* Consistency: Be consistent with the type of quotation marks (single or double) throughout your writing.
In short, starting a sentence with a quotation mark is acceptable in specific situations. It's important to follow the rules of grammar and punctuation to avoid confusion and ensure clarity.