The gerund is a verb form that functions as a noun. It is made by adding -ing to the base form of a verb:
For example:
Swimming is my favorite exercise. I enjoy swimming in the pool. Gerunds can be used as the subject or object of a sentence, or as the object of a preposition:
Subject:
Swimming is good for your health.
Object:
I saw swimming in the pool.
Object of a preposition:
I am not fond of swimming in the cold water.
