occasionally - adverb
Grammar.com's section on the Parts of Speech discusses the demise of -ly adverbs. Click here for that discussion.
Example: She occasionally visited her parents in Oregon.
"occasionally - correct spelling." Grammar.com. STANDS4 LLC, 2017. Web. 23 Mar. 2017. <http://www.grammar.com/occasionally-correct-spelling>.
It’s now more important than ever to develop a powerful writing style. After all, most communication takes place in reports, emails, and instant messages.