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
Since I use it a bunch in my speech, I also want to shout out "viitsisitkö antaa". I don't think there's a proper english word to translate it with, but the closest approximation of the meaning is "could you be bothered to give me" - however while the tone of the translation could easily be read as passive aggressive, if you're just saying it politely, it moreso has this tone of, like... "if you would be so inclined I'd appreciate it".
Which sounds like pretty dramatic appeasement behaviour when I write it out like that but it's also just a nice, polite request, pretty much on par with the "haluaisitko".
One more option is to state "you wouldn't have x" (ei sulla ois x:ää) and that's somehow interpreted as a polite request
But the one thing we don't have is "please". The word doesn't exist here.
You can certainly say "you wouldn't happen to have a [thing] that I could borrow?" in english, too, but I do like how in finnish, the latter half of the sentence is not stated out loud, just implied. You don't word that question like that unless you're asking whether you could borrow it. Which also gives the other person the opportunity to soft launch a "no" by pretending to not notice the implied part. So a conversation can go two ways, it's either:
"Hey wou wouldn't happen to have a hammer?" [Can I borrow your hammer?] "Yeah, what do you need it for?" [You can. What are you working on?]
Or it can go like this:
"Hey wou wouldn't happen to have a hammer?" [Can I borrow your hammer?] "I do own one, yes." [I am ignoring your implied request. Whatever you want to borrow it for, I don't want to let you.] "Can I borrow it?" [I am ignoring your implied rejection. I need to borrow it.] "What do you need it for?" [I will not let you have it unless I know what you want to do and approve of it.]
I don't know how much of this kind of thing is just finnish culture, though, and how much of it is just how neurotypical people universally talk. But the implication waltz is definitely a big part of finnish conversation style.
