Английский Этимологический словарь - please (v.)

- c.1303, from O.Fr. plesir "to please," from L. placere "to be acceptable, be liked, be approved," related to placare "to soothe, quiet." Intransitive sense (do as you please) first recorded 1500; imperative use (please do this) was probably a shortening of if you please. Verbs for "please" supply the stereotype polite word ("Please come in," short for may it please you to ...) in many languages (Fr., It.), "But more widespread is the use of the first singular of a verb for 'ask, request' " [Buck, who cites Ger. bitte, Pol. prasze, etc.] Sp. favor is short for hace el favor "do the favor." Dan. has vжr saa god, lit. "be so good." Pleasure (n.) is c.1370, from O.Fr. plesir "enjoyment, delight," from plaisir (v.) "to please."