A gerund is that form of the verb which ends in ing, and has the force of a noun and a verb.
Uses of Gerunds : -
1. Subject of a verb -
e.g.:- 1. Seeing is believing
2. Hunting deer is not allowed in this country.
2. Object of a transitive verb –
e.g.:- 1. I like reading poetry.
2. Stop playing.
3. Object of a preposition –
e.g.:- 1.He is fond of swimming.
2. I am tired of waiting.
4. Complement of a verb –
e.g.:- 1. Seeing is believing.
2. What I detest most is smoking.
5. Absolutely –
e.g.:- 1. Playing cards being his aversion, we did not play bridge.