The subject of a sentence may be what part sentence?

The subject of a sentence is the noun phrase that performs the action or is described by the verb.

Here's a breakdown:

* Sentence: A complete thought that includes a subject and a verb.

* Noun Phrase: A group of words that acts as a noun. It can be as simple as a single noun (e.g., "dog") or more complex, including modifiers like adjectives (e.g., "the big, fluffy dog").

* Subject: The noun phrase that is the focus of the sentence. It's what the sentence is about.

Example:

* Sentence: The big, fluffy dog barked loudly.

* Subject: The big, fluffy dog (this is the noun phrase that performs the action of barking)