For academic subjects:
* Paksa: This is the most common term for a subject in school or a topic of discussion.
* Asignatura: This is a more formal term for a subject in a curriculum.
For the grammatical subject:
* Paksang-diwa: This refers to the grammatical subject of a sentence.
Other related terms:
* Paksa ng usapan: This means "topic of conversation".
* Paksang-aralin: This refers to a specific topic being studied.
The best term to use will depend on the specific situation. For example, if you're talking about a subject in school, you would use paksa or asignatura. If you're talking about the grammatical subject of a sentence, you would use paksang-diwa.