General terms:
* Pangunahing tauhan: This literally translates to "main character" and is the most common way to refer to a protagonist.
* Bida: This means "hero" or "leading role" and is often used for protagonists in stories.
More specific terms:
* Pangunahing tauhan ng kuwento: This literally translates to "main character of the story."
* Pangunahing tauhan sa kwento: This literally translates to "main character in the story."
* Sino ang nasa gitna ng istorya: This literally translates to "who is in the center of the story."
The best choice will depend on the specific context of your sentence.
For example:
* "The protagonist of the story is a brave knight." could be translated as:
* "Ang pangunahing tauhan ng kuwento ay isang matapang na kabalyero."
* "Ang bida sa kwento ay isang matapang na kabalyero."
It's always best to choose the option that sounds most natural and clear in Tagalog.