Question

is running a verb, gerund, or participle?

Answer 1

How is it used?

Answer 2

It's a gerund because it's a verb ending in ing.

Answer 3

It depends on how it is used....

A participle is a verbal used as an adjective and most often ends in ing or ed.
example : The running water felt quite soothing on my feet. In this sentence, running is used as an adjective modifying water.

A gerund is a verbal used as a noun.
example : Running is great exercise. In this sentence, running is the subject.

A verb is a word which shows action or state of being.
example : Michael was running to the store. In this sentence, running is an action verb.

As you can see, it all depends on how it is used in the sentence. Because it can be a participle, gerund, or a verb.