Why do names of most professions end with er or or?

Many profession names end with "er" or "or" because these suffixes denote someone who performs a specific action or role. The suffix "er" often indicates a person who engages in a particular activity, like "teacher" or "baker," while "or" is commonly used in Latin-derived terms, such as "actor" or "doctor." This linguistic pattern helps to clearly identify the function or occupation of the individual. Overall, these suffixes enhance the clarity and recognition of various professions in the English language.