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

False:

    明天晚上你去老师吗？

    Míngtiān wǎnshàng nǐ qù lǎoshī nà’ér ma

True:

    明天晚上你去老师那儿吗？

    Míngtiān wǎnshàng nǐ qù lǎoshī nà’ér ma?

动词“去” 宾语应是表示处所的词语，“老师”是指人的名词。要在“老师”后加上“这儿”或“那儿”变为处所词语。由于动作“去”是从所在的地方往远处走，只能用“那儿”。

The object of the verb 去 ought to be a word of locality. 朋友 is a personal noun, but it becomes a phrase of locality with 这儿 or 那儿 added to it. Since 去 represents an action in direction of somewhere further away from the speaker, it requires 那儿 as the head word of its object.