[Grammar] Which Preposition to use for specific places?

[enthusiastic learner]

From what I've learned so far, 'At' is used for specific places. Is it still applicable if you are in an enclosed place?

For example,

"I'm at the north wing."

Or, since you are in an enclosed place, you use 'In' instead.

"I'm in the north wing."

Also, one more question. "Those people at the booth should take their seats already." is correct, right?

Thank you in advance!

 

[Tdol]

I'm in the north wing.

At is used for location, but it is not that specific: I'm at home in the kitchen.

 

[enthusiastic learner]

So, is it alright to say: I'm at the mall in the shoe store.

Because what my English teacher told me is, if that is the case, it should be: I'm in the mall at the shoe store.

Thank you for your kind help!

 

[D'Arcy UK]

So, is it alright to say: I'm at the mall in the shoe store.

Because what my English teacher told me is, if that is the case, it should be: I'm in the mall at the shoe store.

Thank you for your kind help!

It usually depends on whether you're thinking of the place as a destination or as a more precise location in an enclosed space. Compare:
"I'm at the exhibition." (a destination or event) and "I'm in the exhibition room/hall." (describing your location in an enclosed space).
"I'm at the north wing." (I've just arrived at my destination, or I'm standing at the entrance) v "I'm in the north wing." (actually inside).
"I'm at the police station." (doing some police business, maybe inside or maybe in the car park outside) v "I'm in the police station." (actually inside, not outside).

 

[MikeNewYork]

So, is it alright to say: I'm at the mall in the shoe store.

Because what my English teacher told me is, if that is the case, it should be: I'm in the mall at the shoe store.

Thank you for your kind help!

That depends on whether you are actually inside of the shoe store. If you are, use "in".