A gerund is the “ing form” of the verb that functions as a noun. We call them verbal nouns also.
We add ing to the end of the base form of the verb. Example: I like speaking English. In this sentence, speaking is a gerund that functions as a noun in the sentence. The main verb of the sentence is like.

Usages of a gerund in the sentence:
1) Subject Complements:
The gerund can be used as subject complements, as in “Her aim is dancing.” In this sentence, the word dancing is a gerund, which is the complement of the auxiliary verb “is”.
More examples:
- Her main hobby is watching TV.
- I like playing football.
- His favorite game is playing piano.
- The man’s first view was jumping for the roof.
- John’s hobby is swimming.
2) Nouns As Subject:
We can use a gerund as the subject of the sentence, too. For example, speaking English is my aim. In this sentence, Speaking is the gerund which occurs as a subject and functions as a noun. Check out more examples.
What is the simple present tense?
- Negotiating is my first rule.
- Smoking is dangerous to health.
- Washing the clothes is her turn.
- Driving fast is not allowed on the road.
- Gaming is his best choice.
- Fighting has been banned in the new park.
3. Gerund used as a Direct Object:
It can occur as the direct object of the verb, also. Like she likes driving fast. In this sentence, driving is a direct object of the verb likes. More examples:
- I have been interested in finding the paper for years.
- They want reading the book to be first on the test.
- She knows knocking on the door well.
- Can she find him swimming in the pool?
- Mehdi enjoys working more than spending time with his friends.
4) Indirect object:
Gerund functions as an indirect object like: I don’t know plugging the flowers. In this sentence plugging is the indirect object of the verb know. And the direct object is plovers.
More examples:
- The teacher gave reading all the time.
- My father likes watering the garden on time.
- He knows the man cooking delicious food.
- The cook found the man cooking delicious food.
- I don’t like working for him.
- Akram likes studying with all of her energy.
5. Objects of prepositions:
How to use gerunds as objects of prepositions? Like: I am afraid of swimming in the sea. In this sentence, 'swimming' is the object of the preposition 'of' which is a gerund. More examples.
- She was worried about speaking in public.
- The man was best at making stylish doors.
- The teachers are perfect at teaching the class.
- All the men are struggling for money.
- He is the best at learning mathematics.
Note: Don’t mix up gerunds with participles.