1-A gerund is a noun made from a verb by adding "-ing"
Reading helps you learn English. (SUB) (VERB) (OBJECT)
Her favorite hobby is reading. (SUBJECT) (Verb) (COMPLEMENT)
I enjoy reading. (S) (V) (O) 2-Gerunds can be made negative by adding "not."
The best thing for your health is not smoking. He prefers not speaking.
3-In the subject position mostly gerunds are used. Learning is important. Dancing is enjoyable.
4- Some verbs are followed by gerunds as objects.
They enjoyed working on the boat.
5- There are many "go + gerund" expressions used for adventure sports and individual recreational activities
I go swimming every weekend.
6- Gerunds are used after prepositions.
He is thinking about studying abroad. Sandy is scared of flying. They admitted to committing the crime.
Adjective+preposition+gerund
Noun+preposition+gerund
Verb+preposition+gerund
7- Gerunds can often be modified with possessive forms such as his, her, its, your, their, our, John's
I enjoyed their singing. She understood his saying no to the offer. Sam resented Debbie's coming late to the dinner. We discussed Mary’s behaving so rude.