When communicating in Chinese you may often make mistakes using Chinese grammar like:

False:

    我在上海里学习汉语。

    Wǒ zài Shànghǎi lǐ xuéxí hànyǔ

True:

    我在上海学习汉语。

    Wǒ zài Shànghǎi xuéxí hànyǔ.

“上海”是地理名称，它的后边不能再用方位词“里”。

上海 is a proper name of place. It can not be followed by a noun of locality as 里 used here.