If you want some to do something, but you do not want to 'order' them to do it you can use wnei di...?, wnewch chi...? (from the verb-noun gwneud):
- Wnei di agor y drws, plîs? Gwna, wrth gwrs - Will you (= can you) open the door, please? Yes, of course.
- Wnewch chi rywbeth i mi? - WiIl you do something for me?
- Wnewch chi ymddiheuro drosto i? - WiIl you apologise on my behalf?