The simple subject of the sentence in the question is brother.
Principal
The simple subject is "brother".
Morning.
Busy
brother
brother
The simple subject of the sentence is "you".
"It can." In that sentence, the pronoun "it" is the simple subject.
"Natives" is the simple subject.
A simple subject is a thing. If it were talking about a Baseball or a sentence the baseball is the simple subject.
The simple subject in the sentence "Did you find your wallet" is "you."