Do following two lines can be used interchangeably for making a polite request.If not,why?
"Could you pass me the salt?"
"Would you pass me the salt?"
Do following two lines can be used interchangeably for making a polite request.If not,why?
"Could you pass me the salt?"
"Would you pass me the salt?"
"Could" and "Would" do technically have different meanings, but in the case of a polite request, they are 100% interchangeable.
Personally, I always follow could you and would you with please, even if my politeness is not sincere.
Could you please pass the salt?
Would you please stop using my salt?!