She does not sleep ( dia tidak tidur/ you have to use "tidak" to negate it because " tidur" is a verb) She did not come ( dia tidak datang/ you have to use " tidak' because " datang is a verb) She is not beautiful ( dia tidak cantik/ 'cantik' is adjective, so you have to use 'tidak' to negate it) He is not smart ( dia tidak pintar/ 'pintar' is adjective, so you have to use ' tidak' if you want to negate it) I am not an Indonesian teacher ( saya bukan guru bahasa Indonesia/ here you have to use "BUKAN" because 'teacher" is a noun) I am Indonesian ( Saya orang Indonesia= literally ' I am indonesian person') I am Australian ( Saya orang Australia) I am American ( Saya orang Amerika)

Bukan is used to negate noun, while tidak is used to negate verb and adjective. You could say " Saya bukan orang Amerika"

Saya bukan orang Amerika. Generally, Bukan = not Tidak = no

Except in a verb <not>, means Tidak