Present Participle (definition)
From Scottish Gaelic Grammar Wiki
In English, this is a verb that combines with the present form of the verb “to be” to indicate an action which is happening in the present. For example, The dog is barking. The people are walking. etc. The present participle can also be used as an adjective, as in The sleeping cat purrs.
See Also
External Links
http://www.usingenglish.com/glossary/present-participle.html
http://en.wikipedia.org/wiki/Present_participle
http://www.tolearnenglish.com/free/news/0gpresentparticiples.htm