Gerund

 A gerund is a verbal that ends in -ing and functions as a noun. The term verbal indicates that a gerund, like the other two kinds of verbals, is based on a verb and therefore expresses action or a state of being. However, since a gerund functions as a noun, it occupies some positions in a sentence that a noun ordinarily would, for example: subject, direct object, subject complement, and object of preposition.
 
Gerund as subject:

• Traveling might satisfy your desire for new experiences. (Traveling is the gerund.)
• The study abroad program might satisfy your desire for new experiences. (The gerund has been removed.)
•   Swimming is my hobby. 
• Your singing is very beautiful.  
• Studying needs time and patience. 
•  Playing tennis is fun. 
•  Reading Japanese is easier than speaking it.
  

Gerund as direct object:

• They do not appreciate my singing. (The gerund is singing.)
• They do not appreciate my assistance. (The gerund has been removed)
•  I enjoy dancing. 
• She likes dancing. 
• Thank you for your coming. 
• I hate arguing

Gerund as subject complement:

• My Dog's favorite activity is sleeping. (The gerund is sleeping.)
• My Dog's favorite food is salmon. (The gerund has been removed.)
•  My favorite sport is running. 
• My favorite activity is reading.

Gerund as object of preposition:

• The police arrested him for speeding. (The gerund is speeding.)
• The police arrested him for criminal activity. (The gerund has been removed.)
•  They are good at telling funny stories. 
• In sleeping I met you in the park.