certainly (part of speech: adverb)
artlessly (part of speech: adverb)
honestly, frankly, unaffectedly, trustingly, straightforwardly, bluntly, openly, artlessly, genuinely, naively, unrestrainedly, sincerely, plainly, candidly, unsophisticatedly, un-artificially, unartfully, directly
- He had begun to call her by her first name quite naturally, as if it were a matter of course. - "The Lion and the Mouse A Story of an American Life", Charles Klein.
- " If you say it is so naturally I am bound to take your word for it," she said coldly. - "The Garden Of Allah", Robert Hichens.
- She rose quite naturally and invited the women to be seated. - "The Merriweather Girls and the Mystery of the Queen's Fan", Lizette M. Edholm.