-ing forms

• as a noun:

I love swimming.
Swimming is very good for your health.
You can get fit by swimming regularly.

-ing nouns are nearly always uncount nouns

• as an adjective:

The main problem today is rising prices.
That programme was really boring.
He saw a woman lying on the floor.

Because the -ing noun or adjective is formed from a verb it can have any of the patterns which follow a verb, for example:

• ... an object:

I like playing tennis.
I saw a dog chasing a cat.

• ... or an adverbial:

You can earn a lot of money by working hard.
There were several people waiting for the bus.

• ... or a clause:

I heard someone saying that.

The -ing noun can be used:

• as the subject of a verb:

Learning English is not easy.

• as the object of a verb:

We enjoy learning English.

Common verbs followed by an -ing object are:

• as the object of a preposition

Some people are not interested in learning English.

The -ing adjective can come:

• in front of a noun:

I read an interesting article in the newspaper today.
We saw a really exciting match on Sunday.

 The commonest –ing adjectives used in front of the noun are

• after a noun:

Who is that man standing over there?
The boy talking to Angela is her younger brother.

• and especially after verbs like see, watch, hear, smell etc.

I heard someone playing the piano.
I can smell something burning.