Use a question mark (?) at the end of your question.
For example:
* "What does this word mean?"
* "Is this sentence grammatically correct?"
Here are some other ways to signal a question:
* Use a phrase like "I'm wondering..." or "I'm curious about..." before stating your question.
* Use bold or italics to highlight the specific part of the text you're questioning.
* Add a footnote to your question if you're writing a formal document.
The best way to indicate your question depends on the context and your audience.