Difference between liese and ruhig
If someone could please explain why and when to use liese and ruhig, I would be very thankful.
"leise" is the opposite of "laut" (loud, noisy). It is not completely silent, that would be "still".
"ruhig" comes from "Ruhe" (calm, rest), so it means calm, relaxed. When you are calm, you don't make much noise, so ruhig implies leise.
Having lived in Germany, I am relating the expressions I heard many times. Also, the first definition of "leise" is "easy" in Langenscheidts dictionary. My Wirtin would say "leise" when she didn't want to be loud for her neighbors; it's not the same as "ruhig", at least as translated into English, my first language. I heard "sei ruhig" a number of times, usually yelled at unruly children. I would say "leise" means "softly" whereas "ruhig" means "quiet, peaceful".
Yes, "leise" is soft-spoken, hushed, muted, low-voice. So "leise" is about sound, or better: lack thereof. You could jump around the room like crazy, as long as you don't make any sound, it would be considered "leise". "ruhig" on the other hand is more general. It includes "leise" and even-tempered, calm, easy.
I generally agree with everyone, but I also think that the difference is pretty minor and not at all important if you want to be understood as a language learner.
"Wir unterhalten uns leise" = We are having a hushed, whispered conversation, e. g. because we're in a library
"Wir unterhalten uns ruhig" = We are having a calm conversation (maybe we fight a lot, but right now we don't)
But in other contexts I would say that they are synonyms. It doesn't make a difference if you tell a child "Sei ruhig!" or "Sei leise!" or even "Sei still!" Theoretically there is the difference that everybody explained, but I think that people don't make a difference if they just want to shush their child ;)
"Still", by the way, means completely silent as well (Stille = silence), but to complicate matters, it's something like a semi-false-friend, since in compounds like "stillsitzen" it's closer to the english meaning and doesn't refer to the noise you make while sitting, but it means that you're sitting without moving. "Der Junge kann nicht stillsitzen" = "The boy can't sit still" or "you need to keep still when the doctor gives you the flu shot" (du musst stillhalten), it's not about being quiet.
Ah, difficult, I love it :D Sorry to you learners ;)
Thanks for your post. The nuances of a language are so interesting. If I may, I would translate "Wir unterhalten uns leise ( oder ruhig )" as "We are having a quiet conversation". And "still"has the same meanngs in both languages. I am minded of the Christmas carol "Stille Nacht" which in English is "Silent Night". I find these explanations so helpful in correcting my errors and broadening my knowledge of German.