Page 87 - Just Enough English Grammar Illustrated Book

The term present participle refers to an action in the present.
As we move to the next principal part, you will find that the
word past in the term past participle indicates an action that
already took place. Keep this distinction in mind when we cover
verb tenses.

4.9 The Fourth Principal Part: Past Participle 4

Base form: walk
I have walked
around the pool. The past participle of a regular verb
follows a pattern: Add -ed to the base
form of the verb.
I have walked around the pool.

Helping Verb Past Participle
Base form: write
He has written The past participle of an irregular verb
a book. follows no apparent pattern: The past
participle must be memorized.
He has written a book.

Helping Verb Past Participle
Walked and written are two examples of past participles.
As past participles, they need a helping verb to be complete.
For past participles, the helping verb is to have. The forms
used with the examples above are have and has. As the second
example shows, the third-person singular verb form changes
from have to has when it connects to he, she, or it.
Have walked and have written are two examples of verb
phrases. They each have a helping verb and a main verb.

Here is a short overview of the four principal parts based on
the two verbs used throughout Part One.

Present Past
Base Form Past Form Participle Participle
Regular
Verb walk walked walking walked
Irregular write wrote writing written
Verb
(needs helping (needs helping
verb to be) verb to have)
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