Gerund as Subject, Object or Complement
Try to think of a gerund as a noun in verb form.
Like nouns, gerunds can be the subject, object or complement of a sentence:
Smoking costs a lot of money.
I don't like writing.
My favourite occupation is reading.
But, like verbs, a gerund can also have an object itself. In this case, the whole expression (gerund + object) can be the subject, object or complement of the sentence.
Smoking cigarettes costs a lot of money.
I don't like writing letters.
My favourite occupation is reading detective stories.
Like nouns, we can use gerunds with adjectives (including articles and other determiners):
pointless questioning
a settling of debts
the making of this film
his drinking of alcohol
When we use a gerund with an article, it does not usually take a direct object:
a settling of debts (not a settling debts)
Making this film was expensive.
The making of this film was expensive.
Do you see the difference in the following two sentences? In one, "reading" is a gerund (noun). In the other, "reading" is a present participle (verb).
My favourite occupation is reading.
My favourite niece is reading.
Explanation