Uses:

• To make our writing and speaking more economical, efficient, and more elegant.

• To add information about reason, condition and result.

Present Participles (ing)

They have an active meaning.

Reduced Relative Clauses: (same purpose as adjectives)

Example:

"The woman who is smiling in the photo is my grandmother".

"The woman smiling in the photo is my grandmother".

"I smelt the bread that was burning"

"I smelt the burning bread"

"I liked the CD (that was) lent to me by a friend"

Present Participles (ing)

Adverbial Clauses: (like adverbs) They express manner, conditions, cause, result, etc. They are common in formal or literary texts. To make it negative, use NOT before the present participle.

Example:

• To give the result of an action
  The bomb exploded, destroying the building.

• To give the reason for an action
  Knowing she loved reading, Richard bought her a book.

• To talk about an action that happened at the same time as another action
  Standing in the queue, I realised I didn't have any money.

• To add information about the subject of the main clause
  Starting in the new year, the new policy bans cars in the city centre.

Past Participles (ed)

They have a passive meaning and add extra information. Sometimes they have the same purpose as adjectives (describing a noun).

Example:

• With a similar meaning to an if condition
  Used in this way, participles can make your writing more concise. (If you use participles in this way, … )

• To give the reason for an action
  Worried by the news, she called the hospital.

• To add information about the subject of the main clause
  Filled with pride, he walked towards the stage.

Having + Past Participle

Perfect participle clauses show that the action they describe was finished before the action in the main clause. Perfect participles can be structured to make an active or passive meaning.

To show the cause of a second action.

Example:

"Having won every competition, he decided to retire".

To show a sequence of actions.

Example:

"Having made breakfast, she sat down and read the paper".

Participle clauses after conjunctions and prepositions

It is also common for participle clauses, especially with -ing, to follow conjunctions and prepositions such as before, after, instead of, on, since, when, while and in spite of.

Example:

Before cooking, you should wash your hands. 
Instead of complaining about it, they should try doing something positive.
On arriving at the hotel, he went to get changed.
While packing her things, she thought about the last two years.
In spite of having read the instructions twice, I still couldn’t understand how to use it