You need a question mark inside the speech bubble if the spoken words form a question.
* Example: "Where are you going?"
You do NOT need a question mark inside the speech bubble if the spoken words are a statement, even if they sound like a question.
* Example: "You're going where?" (This is a statement expressing surprise, not a question.)
Here are some additional considerations:
* Punctuation in speech bubbles generally follows the same rules as regular writing. This means using commas, periods, exclamation points, etc. as needed.
* Be careful with dialogue tags. If you use a dialogue tag like "he asked" or "she exclaimed," you may need to adjust the punctuation within the speech bubble.
* Consider context. If the tone of the speech bubble is clear from the surrounding text or image, you may not need a question mark even if the spoken words are a question.
Ultimately, it comes down to making your speech bubble clear and understandable for the reader.