Here's why:
* Adjectives describe nouns: "Dangerous" describes a noun, such as a "situation," "animal," or "activity."
* Verbs show action or state of being: A verb tells what something *does* or *is*. For example, "run," "think," "exist."
You might use "dangerous" in a sentence like this:
* "The lion is a dangerous animal."
Here, "dangerous" describes the noun "animal."