Inc. All rights reserved. A gerund always ends in ing and is used as a noun.
Eating is fun.
A participle is used as an adjective and ends in various ways. A present participle always ends with ing as does the gerund, but remember that it is an adjective. A past participle ends with ed, n, or irregularly. An infinitive is to plus a verb form. It can be a noun, an adjective, or an adverb.