Generally, question marks are used at the end of a sentence that is asking a direct question.
However, there are a few instances where a question mark might appear mid-sentence:
* Indirect questions: These are questions that are not directly asked, but rather reported as statements. For example: "I wondered what time it was?"
* Rhetorical questions: These are questions that aren't intended to be answered, but are used to make a point. For example: "Is this really the best option?"
* Expressing uncertainty or doubt: You can use a question mark to emphasize a point of uncertainty. For example: "He said he would be here at 7, but is he?"
* Informal writing: In informal writing, especially online, people sometimes use question marks mid-sentence to express surprise, emphasis, or even sarcasm. For example: "Wow, that's amazing?"
It's important to use question marks mid-sentence thoughtfully and sparingly. Overuse can make your writing confusing or informal.