Regional vocabulary differences

Standard Mandarin is understood everywhere, but everyday words shift between regions. The north says 哪儿 (nǎr) with heavy erhua; the south prefers 哪里 (nǎlǐ) and drops the -r endings. A bicycle is 自行车 in the north and often 单车 in the south; tomato is 西红柿 in the north, 番茄 in the south; a potato can be 土豆, 马铃薯, or 洋芋 depending on where you are. Money is counted as 块 (kuài) in speech everywhere, while 元 (yuán) stays formal and written.

None of these are wrong anywhere — locals understand both — but noticing them explains why real speech differs from your textbook, and matching the local word makes you sound instantly more natural.