I'm not sure how to phrase this, but nouns, verbs, adjectives are all what in a language?

[BigToque]

I know what they are, but I don't know what you would call the heading that these would fall under. Is there a heading?

If I wanted to learn more about language structure in general, what would I look for?

 

[b0mbrman]

Lexical (or linguistic) category

 

[giantpinkbunnyhead]

I would say that they are classes.

If you look noun or adjective or verb up, the definitions all begin "any of a class of words which..."

 

[Krazy4Real]

words.

 

[sdifox]

Lingustics is what you should look for. I believe Syntax covers those things. They are called Part of Speech.