Onomatopoeia:
* Gasp! - This is the most common and direct way to write a gasp.
* Gasp - This is a more understated way to represent a gasp.
* Ugh! - This can be used for a gasp of surprise or disgust.
* H-h-h-h- - This emphasizes the shortness of breath and suddenness of the gasp.
* Oh! - This can be used for a gasp of surprise or excitement.
Descriptive words:
* He gasped.
* She let out a gasp.
* A gasp escaped her lips.
* He drew in a sharp breath.
Using punctuation:
* "Gasp!" she exclaimed.
* He stared in disbelief, his eyes wide with… gasp!
Ultimately, the best way to spell a gasp sound depends on the specific context and the desired effect. Consider the emotion being conveyed, the intensity of the gasp, and the overall tone of your writing.