As a noun (subject or object of a verb)

After a preposition or verb + preposition

After certain verbs (as their object): admit, appreciate, avoid, consider, delay, deny, discuss, dislike,...

After verbs or expressions with to: be/get accustomed to, be/get used to, in addition to, look forward to, object to, take to,...

After certain expressions: as well as, be in favor of, can't stand/help, feel like, have difficulty (in), how about, It's no good/ use, it's worth, there's no chance of, there's no point in,

After the verbs need, want, require, etc. with a passive meaning

After the verbs: catch/ find/ leave + object + V-ing

After the verb go, indicating physical activities.

Be busy + V-ing Spend/ waste + expression of money/ time + V-ing