Present participles

Formation

The present participle is formed by adding the ending "–ing" to the infinitive (dropping any silent "e" at the end of the infinitive):

to sing –> singing
to talk –> taking
to bake –> baking
to be –> being
to have –> having

Use

A. The present participle may often function as an adjective:

That's an interesting book.
That tree is a weeping willow.

B. The present participle can be used as a noun denoting an activity (this form is also called a gerund):

Swimming is good exercise.
Traveling is fun.

C. The present participle can indicate an action that is taking place, although it cannot stand by itself as a verb. In these cases it generally modifies a noun (or pronoun), an adverb, or a past participle:

Thinking myself lost, I gave up all hope.
Washing clothes is not my idea of a job.
Looking ahead is important.

D. The present participle is used in progressive verb tenses, which indicate continuing actions or actions in progress (the present progressive, the future progressive, the present perfect progressive):

I am eating my dinner.
He was walking across the park.
We will be calling you tomorrow.

E. The present participle may be used with "while" or "by" to express an idea of simultaneity ("while") or causality ("by"):

He finished dinner while watching television.
By using a dictionary he could find all the words.
While speaking on the phone, she doodled.
By calling the police you saved my life!

F. The present participle of the auxiliary "have" may be used with the past participle to describe a past condition resulting in another action:

Having spent all his money, he returned home.
Having told herself that she would be too late, she accelerated.