General rule:
* Direct speech: When you quote someone's exact words, you use quotation marks and a full stop at the end of the quote.
* "I'm going to the store," she said.
* He asked, "What time is it?"
Exceptions:
* Interrupted speech: If a sentence is interrupted by an action or description, the full stop goes after the interrupting phrase, not after the speech.
* "I'm going to the store," she said, "to buy some milk."
* Speech followed by a question mark or exclamation mark: If the speech is a question or exclamation, the question mark or exclamation mark replaces the full stop.
* "Are you coming?" he asked.
* "That's amazing!" she exclaimed.
* Speech followed by a comma: If the speech is followed by a phrase that explains who said it, the comma replaces the full stop.
* "I'm going to the store," she said.
Important note: In informal writing, like text messages or social media posts, full stops after speech are often omitted. However, it's still good practice to use them in formal writing.