Ответ:

VerbOnly add -ingRemove -e and add -ingDouble the consonant and add -ing-ing form
dance✓dancing
get up✓getting up
have✓having
make✓making
open✓opening
play✓playing
shop✓shopping
sit✓sitting
swim✓swimming
watch✓watching

The spelling rules determine whether we simply add -ing, remove final -e, or double the final consonant.