The small girl is running Is an adjective?

No, "running" is not an adjective in the sentence "The small girl is running."

Here's why:

* Adjectives describe nouns. In this sentence, the noun is "girl."

* "Running" is a verb, which describes an action. It tells us what the girl is doing.

Here's an example of how "running" could be used as an adjective:

* "The running girl" - Here, "running" modifies the noun "girl" and describes her as a girl who is running.