Couldyouplease是canyouplease更为礼貌、委婉的说法,并不是过去式,是“能否麻烦你……”、“请你……”的意思,更侧重“能否”及客观情况；回答时要注意,eg：A:“Couldyoupleaseopenthewindow?”肯定回答B:“Ofcourse”；否定回答：B:“Sorry,Ican'topenitbecausethewindowsarelockedonthetrain.”

　　而Wouldyouplease含有说话者一定的希望,期待对方愿意做某事的意味,“请你……”,更侧重“愿否”及主观能动；回答时要注意,eg：A:“Wouldyoupleaseopenthewindow?”肯定回答：B:“OK”；否定回答：“I'msorry,butdon'tyoufeelitisalittlebittoocoldoutside?”

　　尽管两者有小小差异,但是在日常口语中,似乎两者经常通用,并没有区分得那么明显.