Question

how to do the gerund sentences​

Answer 1

use ing form at beginning

Answer 2

Recognize a gerund phrase when you see one.

Eating ice cream on a windy day can be a messy experience if you have long, untamed hair.

Eating ice cream on a windy day = subject of the verb can be.

A more disastrous activity for long-haired people is blowing giant bubble gum bubbles with the car windows down.