Most Westerners, including me, in the first few months in China, mispronounce the anglicized spelling of Chinese sounds and, thus, Chinese words.  the word, Yuan, for example, which is the name of Chinese money, is properly pronounced "U-en", not "U-ahn".  The Yuan, by the way, is also called the Remen Bi, which means, literally, the peoples' coin,  In China, also, people will often the word "kuai", instead of Yuan, so yi bai kuai = yi bai Yuan = Y100.  To complete your education on the Yuan, we point out that its currency code in the foreign exchange markets is CNY.

Other sounds that people commonly mispronounce are: xi = somewhere between si and she, zh = dje, z = dz not just z. 

You can learn some rudimentary Chines (Mandarin) on the Chinese Language Page of the Leona Craig/In Country-China/Red Hill website.