found a great explaination. Want to shared it with you all.

Question

Finding Partciple   
 First and foremost, a participle is the form of a verb, but it is not a verb. Second, it is an adjective. And finally, it ends in "ing" or "ed" or "en." 
 
• As the colonies  became  a new nation  dedicated  to the proposition that all men are created equal, public schools had another purpose.
o First find the subject and verb of each clause: COLONIES BECAME and SCHOOLS HAD. With that done, we can see that DEDICATED is not the subject. Instead, it describes the word NATION. Therefore, it is an adjective. A form of a verb that ends in ED, EN or ING and acts as an adjective is a participle.

•  Transformed  by the national economy, urban factories  developed  a need for disciplined, obedient workers.
o The subject (factories) DEVELOPED. So what does TRANSFORMED do? It describes FACTORIES.

•  Learning  to solve problems in groups, the students  began  to understand how to fit within the social structure.
o Identify the subject and verb. What is this sentence about? STUDENTS. What is the verb? BEGAN. What part of the sentence does LEARNING go with? The subject. It describes STUDENTS, so it is a form of the verb acting as an adjective—a participle.

The steps to finding a participle:
1. Find the subject and verb to eliminate any confusion.

o Al Gore, knocked around by Bill Bradley for being "pro-gun," is confidently pushing gun control to the forefront of his presidential campaign.
 AL GORE is the subject. IS PUSHING is the verb. KNOCKED is a form of the verb, acting as an adjective, modifying Al GORE - therefore it is participle.

o The activist called for a waiting period for gun purchases to help reduce illegal gun trafficking. 
 The subject is ACTIVIST. The verb is CALLED. WAITING is a form of the verb, acting as an adjective, modifying PERIOD.

o Headed by conservative media watchdog leader Brent Bozell, the Parents Television Council announced the results of a study.
 The subject is THE PARENTS TELEVISION COUNCIL. The verb is ANNOUNCED. HEADED is a form of the verb, acting as an adjective, modifying the subject.- headed is participle .

o The network reported on the springtime ritual of young men and women flocking to warm beaches around the globe.
 The subject is NETWORK. The verb is REPORTED. FLOCKING is a form of the verb, acting as an adjective, modifying men and women. It can't act as a verb without an auxiliary verb. For example: Young men and women WERE flocking to warm beaches.

Gerund 
Gerund = ing form of the verb.
How to differentiate between Present participle and a Gerund
Present participle = describes present condition

Eg - Typing letters, she has grown old. 
This sentence describes present condition – at present she is old.

If – ing form of the verb is there and it does not not describe present situation then it must be a gerund.

Eg- Reading a book is a hobby for many.
Infinitive VS Gerund
Gerunds are used to describe an "actual, vivid, or fulfilled action" whereas infinitives are better used to describe "potential, hypothetical, or future events"

We began working on this project two years ago.- Gerund
We will continue to work on this project for the next four months- infinitive

In case you wish to know how to find the subject of a sentence :

How to find the Subject in a sentence

When finding the subject and the verb in a sentence, always find the verb first and then say who or what followed by the verb. Example: The bell rang. Find the verb - rang. Now say who or what rang? The bell rang. Bell is the subject

gmatopoeia · Answer

Thanks for this! :-D

viks4gmat · Answer

yup... thanks for the lovely post.. kudos to you!!

daagh · Answer

First, I would call it a very good effort to explain an intricate concept. Although I may have some difference in what the passage says, still it is an excellent involvement and deserves a well-earned kudos. 
However, a few things I would like to delve into: 
Participles both present and past are never verbs; they are called verbals.
The nomenclature present or past is only a technical description and never a tense- marker. For example, a present participle ending in 'Ing' form need not indicate present tense. It can also be used in past situations. Similarly, a past participle can be very well used in present situations.

Eg:  Worried  about the toughness of the GMAT, test takers are frustrated these days. : See how the past participle worried is used in a present situation.

Taking the opposition head-on, Abe Lincoln emancipated the Blacks from the clutches of slavery: See how the present participle ' taking ' is used in a past situation. 
Therefore, the example that “ Typing  letters, she has grown old” does not indicate present tense as pointed out in the note. , But 'she has grown old' indicates a present perfect tense, but it isn't logical to say that she has grown old or is growing old while she keeps typing.

Since present participle is not a present- tense marker, the problem of differentiating a present participle from a gerund turns all the more tricky.

Present participle

When the verb+ing form or its phrase acts an adjective, modifying a noun, then it is a present participle.

Singing a song, Tom walked along the river.
Shouting abuses, Dick tried to browbeat Harry
By sending a bouquet, the students expressed their love for their teacher.

Here, the ‘ ing ’ forms modify a noun that is placed next to the comma. These are all present participles.

Gerund

On the contrary, when the ‘ ing ’ form is followed by a verb or verb phrase then it will be gerund.

Going  by his words will lead to wrong conclusions 
Shopping on week- ends is cumbersome because of heavy crowds.

Here are some ways to split between a gerund and a present participle.

As a gerund is essentially a noun trying to do an action, we can apply some of the attributes of a noun and see whether the ‘ing’ form fits within the parameters of the noun.

A. The first such test is whether the ‘ing’ form acts as a subject or object.

Singing  is a pleasant entertainment

Here singing is the subject of a simple sentence; only a noun or a noun phrase can act as the subject of a clause. Hence, in the given context, ‘singing’ is a gerund

B. See whether the ing form is an object

Tom likes  singing  
Singing is the object of the clause; it is a gerund 
C. See whether it has any adjective preceding it, especially in the form of a possessive pronoun

Tom feels that  his singing  is better than many others’ are

Here the ing form singing is modified by the possessive pronoun ‘his’. Hence, singing is a gerund.

D.Sometimes an article is gerund - marker. See whether the ing verb is preceded by an article such as ‘the’ 
‘ The shopping’  at the Spencer’s is a delight.

E. See whether the  ing  word can be replaced by the word  ‘it’  and the sentence still completes the meaning. Replacing he gerund with the pronoun  ‘it’  can complete the meaning while a participle cannot.

Singing is a good past time

Here we can replace  singing  with the pronoun  it  – It is a good past time.

F... see whether the  ing  word or the entire  ing  phrase can be replaced by the word ‘ something ’

Singing  along the riverbank, Tom jogged for nearly four miles in one hour
(Singing)  Something  along the riverbank, Tom jogged for nearly four miles in one hour

(Singing along the river bank) Something, Tom jogged for nearly four miles in one hour

When you replace the ing word or phrase with something, nothing meaningful turns out. Therefore, the phrase starting with singing cannot be a gerund.

Now try this.

Signing along the riverbank is a refreshing pastime

After replacing the  ing  phrase, the sentence reads as (Singing along the riverbank) something is a refreshing pastime

Now you can see there is some meaning in the clause. Therefore, the  ing  phrase is a gerund in the context.

raghavakumar85 · Answer

Thanks for the explanation daagh.

pankgarg · Answer

Thanks everybody for your comments and kudos on this post; I need some more of those (is this the right usage ? I guess yes, remember "Those Vs Them :-)

, I will soon share some more helpful tips.

alchemist009 · Answer

what a great post. it makes easy to understand one of most intricate topic in gmat.

vv65 · Answer

Excellent thread on verbs and participles and gerunds

found a great explaination. Want to shared it with you all.

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