Read the following sentence

• Reading is my hobby.

Reading is a verb ending in -ing. At the same time it is the subject of the verb is and hence acts as a noun. Such a form of the verb ending in -ing and used as a noun is called a gerund or verbal noun.

Forms of the gerund

The gerund has different forms

• I like swimming. (Present, active)
• Being shot is no fun. (Present, passive)
• He was charged with having shot a policeman. (Present perfect, active)
• His having been shot at made him nervous. (Present perfect, passive)

Notes
The gerunds you see in sentence 2, 3 and 4 are called compound gerunds. They are not very often used.

Uses of the gerund

As the subject of a verb
A gerund may be used as the subject of a verb.

• Singing is her hobby.
• Walking is good for health.
• Smoking is injurious to health.

As subject complement

• My mistake was trusting him.
• My top priority is getting a good job.

As the object of a verb

• I like reading.
• I enjoy swimming in the sea.

As the object of a preposition

• I am thinking of visiting Canada.
• He was punished for lying.

In apposition to a noun

• His crime, stealing a policeman’s helmet, was considered serious.

Related posts:

1. Gerund and Infinitive
2. Non-finite verbs