in the building? at the building?

[tzwgxl]

Hello, I joined because I have a question that befuddle me though I speak English as my first language. In the sentence below, is it correct to use 'at' as well?

This is the building where my dad works in/at.

Help!

 

[bhaisahab]

Neither one is correct in that sentence. "This is the building where my dad works" is fine as it is.

 

[tzwgxl]

I'm sorry. What if I use 'which' instead of 'where'?

This is the building which my dad works in/at.

:shock::-o:-o

 

[Rover_KE]

You can use either in or at in that sentence. I prefer in.

 

[Roman55]

I am not a teacher.

You can also say, 'This is the building my dad works in' without the 'which'.