A heretic
A heretic is someone who has a part of their heritage but doesn’t look like they belong. They might speak the language but not perfectly. They’re kind of a mix of things.
My friend’s mom is a heretic because she’s partly French but doesn’t speak French.
My uncle is a heretic because he was born in Italy but doesn’t know how to cook pasta.
My cousin is a heretic because she speaks Spanish but only a little.