The word "可以" is formed by combining the character "可", meaning "can" or "may", which conveys possibility or permission, with the character "以", meaning "by means of" or "with", which historically indicated a method or basis. Together, they create a compound where "以" reinforces the modal function of "可", resulting in a word that means "can" or "may" and is used to express capability, permission, or feasibility.