certainly

UK: /ˈsɜː.tən.li/ | US: /ˈsɝː.tən.li/

Definition
  1. adv. without doubt; definitely

  2. adv. used to emphasize agreement or acknowledgment

Structure
certain <sure, fixed>ly <adverb suffix>
Etymology

certainly = certain<sure, fixed> + ly<adverb suffix>

  • certain: From Old French certain, derived from Latin certus (fixed, settled, sure), from the past participle of cernere (to decide, discern).
  • ly: A common English adverb-forming suffix, from Old English -līce (having the quality of).

Etymology Origin:
The word "certainly" evolved from the Latin certus, which originally meant "decided" or "resolved." Over time, certus entered Old French as certain, retaining its sense of sureness. The suffix -ly was added in Middle English to form an adverb, solidifying its modern meaning of "without doubt." The progression reflects a logical shift from concrete decisions (cernere = to decide) to abstract certainty.

Examples
  1. She will certainly arrive by noon.

  2. "Would you like some tea?" "Certainly!"

  3. The project is certainly challenging but worthwhile.

  4. He certainly knows how to make an impression.

  5. This is certainly the best option available.