Where does “certifico” come from?

certifico (Medieval Latin) comes from Latin certus, from Proto-Indo-European krey- — to sift, separate, divide.

Ancestry of “certifico”, step by step

StepLanguageWordMeaning
1Latincertuscertain; fixed, settled, firm; resolved,...
2Proto-Indo-Europeankrey-to sift, separate, divide
Every word from Proto-Indo-European krey- →Every word from Latin certus →
certifico — Etymology, Origin & Word History | Etymology Explorer