Sir, <br/><br/>1.Would you do me a favour? <br/>2.Would you mind opening the window? <br/><br/>Can I replace "would" with "could". <br/><br/><br/>i.e <br/><br/>3.Could you do me a favour? <br/>4.Could you mind opening the window? <br/><br/>are all convey same meaning. <br/><br/>Thanks. <br/><br/><br/>