how do I highlight and single out words without covering half the page? 11 Pro to DC Pro

Our user went from Adobe Pro 11 to Adobe DC Pro or the latest edition of Adobe Pro. The user states that they used be be able to easily highlight and single out words without having to cover half the page.  She saves docs to PDF and all docs act the same. I'll send here the link to this post to see if anyone has any comments and suggestions.