The fun thing about finnish is that the way you ask for things in a polite way has been in-baked into the suffixes you use, so you don't have to use many words when few do trick. Like asking someone "could you give me [-]" is "voisitko antaa" in written and some variation of "voisiksä antaa" in spoken dialects*, but instead of asking "could you", the polite polite way to ask is "haluaisitko", not as can you, but would you want to. The tone distinction is so clear that asking someone "could you [do thing]" instead of "would you want to [do thing]" is less of a polite request and more of instruction - someone's gotta do it, and the task is being assigned to you.
On the other hand, dropping out the conditional out of the question turns the tone into a passive-aggressive threat. If someone tells you "stop that" as an imperative, "lopeta", that's a command. Asking in conditional, could you stop that, "voisitko lopettaa" is a polite request. "Haluaisitko lopettaa", would you like to stop that, is so polite that depending on the tone it might be sarcastic politeness that indicates hostility.
But asking someone "do you want to stop that", "haluatko lopettaa tuon" is a matter of "do you want to stop doing that voluntarily, or do you want me to stop you." By physical force, if necessary.
* the different form varies depending on what first and second person pronouns are used in the specific dialect. This is a whole another rabbit hole so for shortcut I'm doing the examples in the southern finnish dialect that I have grown up speaking
Now this is interesting to me... because the Finnish-edition title for So You Want To Be A Wizard is Haluatko velhoksi?...
