Usages of nǎr
你们 在 哪儿？nǐmen zài nǎr?
Where are you?
您 在 哪儿 工作？nín zài nǎr gōngzuò?
Where do you work?
你 现在 在 哪儿 呢？nǐ xiànzài zài nǎr ne?
Where are you now?
Elon.io is an online learning platform
We have an entire course teaching Chinese grammar and vocabulary.