Grammar: -ing form

We use the -ing form

• as the subject of a sentence. Reading a book is more tiring than watching a movie.
• after avoid, appreciate, consider, continue, deny, go (+ activities), imagine, keep, miss, save, suggest, practice, prevent, spend/waste (time/money) on, etc.                                               Can you imagine working in a chocolate factory? 
• after prepositions. I am interested in going to the book festival.
• after verbs that express like/dislikes, such as: can't stand, like, enjoy, etc.  I like reading novels.
• after phrases such as: can't help, look forward to, it's no use, it's not worth, have difficulty. I can't help laughing at the joke.