When Norman French started to enter English around1066, the idea of courteous behavior also entered the language. An example would be the move toward switching between “you” and “thou” to appropriately show respect or intimacy, modeled on the French tu/vous distinction.

This concept of courtesy was central to how one expressed gratitude and, by the time we arrived in the early modern era (the time of Shakespeare), thanking was firmly established. However, routinely responding to those thanks was not common. If uttered at all, we’d more often hear something like a deferential, “I am but your humble servant.”

In the 18^th century, elaborate complimenting routines became popular, and by the late 19th and early 20th century, English-speaking society had a greater focus on treating all people as equals. As a result, being aware of how one’s actions might impose upon others became increasingly important.

Requests that were once directly stated as imperatives were now couched with indirectness as merely suggestions or questions: “Shut the window,” became “Could you please shut the window?” And, in addition to saying “thanks,” responding with an acknowledgment of that thanks, such as “you’re welcome,” became routine.