When we talk about the nominative case, we're talking about the way we use words that are the subject of a sentence.
For example, let's say we have a simple sentence like "The cat meowed." In this sentence, "cat" is the subject - it's what the sentence is about. And when we use a word as the subject of a sentence, we use a special form called the nominative case.
So in this case, "cat" is in the nominative case - it's just a regular old noun that we all know and love. But some words change when they're used in the nominative case. For example, let's look at pronouns.
Pronouns are words like "I," "you," "he," "she," "it," "we," and "they" - they're used to replace other nouns. And when we use them as the subject of a sentence, they often change to show that they're in the nominative case.
For example, "I" becomes "me" in other contexts, but when it's the subject of a sentence, it becomes "I" again. "He" and "she" don't change, but "it" becomes "it," "we" becomes "we," and "they" becomes "they."
So when we're talking about the nominative case, all we're really talking about is how certain words change when they're used as the subject of a sentence. It might seem a little confusing at first, but don't worry - you'll get the hang of it in no time!