-ING

1. -W, -X, -Y or when the final syllable is not emphasized + ING    
2. -Consonant+Vowel+Consonant and when the stress is on the final syllable = -Consonant+Vowel+Consonant+Consonant+ING
3. -L = -LL+ING
4. -IE = -Y+ING
5. -E = -ING
6. Stressed vowel+R = RR

1. To enjoy - enjoying                                       To fix - fixing                                                    To snow - snowing
2. To run - running                                            To begin - beginning                                         To stop - stopping
3. To travel - travelling (UK) traveling (US)    To marvel - marvelling (UK) marveling (US)
4. To die - dying                                                To lie - lying                                                      To tie - tying
5. To make - making                                         To live - living                                                   To move - moving
6. To refer - referring                                        To defer - deferring