If in php i can create something like parentClass -> childCluss -> sbuChildClass in inheritance? Or child can have only one parent ?

somthink like:

class base {
    function connection();
}
class child extend base {
    function check_some(){
        $tmp = parent::cpnnection();
    }
}
class subchild extend child{
    function check_else(){
        check_some();
    }
}

I know that in Java i can create some subchild and use a child or parent methods but in php i tried and it faild.

in my example it must connect to db with pdo and it return datal error prepare() null