tu hermano es inteligente
The word for street smart is: vivo(a).
Hermano is brother in Spanish
el es inteligente
perro inteligente
Ella es inteligente.
'hermano' is the usual word for brother
el hermano
It would depend on the context, but to use "smart" as an adjective you should say inteligente.
No es inteligente Inteligente no es
Hermano. Sister is Hermana
hermano feo
hermano chocolate