Verbs:
* Action verbs: running, swimming, singing, dancing, sleeping, eating, talking, writing, reading, playing, laughing, crying, thinking, knowing, doing, being, going
* State of being verbs: feeling, seeming, looking, sounding, becoming, remaining, belonging
Nouns:
* Gerunds: swimming (the act of swimming), baking (the act of baking), reading (the act of reading)
* Other nouns: morning, evening, anything, something, nothing, anything, everything
Adjectives:
* Present participles acting as adjectives: interesting, exciting, surprising, amazing, frightening, confusing, annoying, relaxing, demanding, charming
Other words:
* Adverbs: according, regarding, concerning
* Prepositions: during, concerning
This is just a small sample - there are many, many more words ending in "-ing"!