Using the classifier ge
Hello everyone, I don't know why it isn't used the classifier ge in the next sentence;

- Ni shi na (ge) guo ren?

I understand that guo ren IS a noun (nacionality), so I don't get why there is no classifier used the same way as it is used in the next one:

- Ni qu nage guojia?

Being guojia also a noun (country).

Thank you all!

Question

Using the classifier ge
Hello everyone, I don't know why it isn't used the classifier ge in the next sentence;

- Ni shi na (ge) guo ren?

I understand that guo ren IS a noun (nacionality), so I don't get why there is no classifier used the same way as it is used in the next one:

- Ni qu nage guojia?

Being guojia also a noun (country).

Thank you all!

Answer

it's not "guo ren IS a noun" -- nope

it's 
nǎ = which
guó = country
rén = person

and
the classifier is used between the number and the noun
or
the indicative pronouns "this / that" and the noun
only

Answer

In my opinon,You can say ´´ni shi na ge guo jia de ren?´´, but usually we would say ´´ni shi na guo ren?´´ which is kind of like the short form of the former sentense. ´´na guo´´ means which country 
´´ge´´ is the measure word. 
and for ´´ni qu na ge guo jia?´´, you can also say ´´ ni qu na guo?´´

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