Here's why:
* It modifies verbs: It tells us how often or how frequently something happens. For example: "I sometimes go for walks."
* It can modify adjectives and other adverbs: "It's sometimes difficult to make decisions." (modifies the adjective "difficult")
* It can also be used as a conjunction: "I'll go to the party, sometimes." (connects two clauses)
Let me know if you have other words you'd like to identify!