- Joan was punished for CHEATING.
- His favourite sport is SWIMMING.
- They called my PLAYING brilliant.
- READING is an important skill.
- We have our consent in WRITING.
- For most birds, FLYING is a way to escape predators.
- Her SINGING is hurting my ears.
- The team practiced RUNNING on Friday.
The definition of a gerund is a verb that ends in -ing that acts like a noun, such as with these sentences.