Here's why:
* Subject: The subject of a sentence is the person, place, thing, or idea that performs the action of the verb. It answers the question "who?" or "what?".
* Nouns: Nouns are words that name people, places, things, or ideas.
Example:
* The dog barked loudly.
* "The dog" is the subject of the sentence, and "dog" is a noun.
Of course, nouns can appear in other parts of the sentence, but the subject is where you'll most often find them.