Zhe/zhei and na/nei

你好 I'm having trouble distinguishing the difference in usage between zhe (这) and zhei (same character, I think). I also can't tell the difference between na (那) and nei (哪). When I was taking a class, I asked my teacher about this but she could not explain it. Can anyone help? Thanks!

这 and 那 can be pronounced either zhe/na or zhei/nei. It is just more colloquial to use zhei/nei. As a side note, I noticed you listed 那 and 哪 out with different pinyin pronunciations as if you must use one for questions and the other for declarative sentences. I don't know if this was intentional but in fact either (na/nei) can be used for either declarative or interrogative.

na(那) denotes declarative and 哪 which can also be pronounced as na denotes question. For example, wo zai na li.我在那里。I am there./ ni zai na li? 你在哪里？Where are you？

你好！ Thanks again Oggie and also to Wei for your explanations. I hope this has helped you Michael as I myself couldn't explain it better. 加油！ 再见！