's' in "cosa"
All the times I've heard this word, including variations like "cos'è" and "cos'hai", on DL it sounds like /ˈkɔza/, with a voiced fricative. However, I looked on WordReference and it gives the pronunciation as /ˈkɔsa/ and the audio sample has a /s/ in it. Can someone tell me if "/ˈkɔza/" is right or if I've just been hearing wrong/bad audio on DL.
EDIT: Well I guess I kind of found the answer. Wiktionary says that northern Italy pronounce it with a /z/ and central and southern Italy pronounce it with a /s/, which they indicate to be the "standard". I guess our voice recorder is from the North. Also I've found that other words are included in this discussion as well, like "famoso"
I can confirm what Wiktionary says about this word.
The correct pronunciation is /'kɔsa/, which is heard in most parts of central Italy and in the south-west of the country. It is usually pronounced /'kɔza/ in the north, with some other regional variants such as /'kɔʂa/ (Emilia Romagna), or /'ko:sa/ (Puglia).
The same phonetic difference between north and center-south is true for most words in which the letter 's' stands between two vowels. But in some cases the correct pronunciation is /z/, as in caso, which is pronounced /'kazo/ in the north, and /'kaso/ in the center-south.
By the way, Duolingo's recorded sample usually sounds as standard Italian, without any regional inflection. I listened to a few sentences that include cosa and it seemed to me as if the pronunciation was midway between /s/ and /z/.
It's a pretty subtle difference between cosa and coza, especially when spoken at "native speed" (which is to say, incredibly fast).
There's an old Newfoundland (Canada) saying: "I'm not speaking too fast, you're listening too slow!"
In reality, since there is no Italian word spelled "coza" then it doesn't really matter if you say or hear cosa or coza.
It has to mean "thing".
The pronunciation of the "S" varies a lot from region to region. I believe that in northern Italy the sound /z/ tend to be predominant over the sound /s/, while in southern Italy it should be the opposite.
In standard Italian, the letter "S" is general pronounced /z/ when it's between vowels. However, this "rule" (if we can call it this way) has tons of exception. One of them is the word "cosa", and same happens for "casa" and for "così". The "S" is pronounced /s/ also in the adjectives ending in "-oso" (despite I know that many actors like to pronounce -oso with a /z/ because it sounds better).
Rules about the pronunciation of the "S" are very complicated, and most Italians don't know them and don't follow them, so I would suggest you not to focus on those rules too much.