You can create a login failed action hook,
// hook failed login
add_action('wp_login_failed', 'my_front_end_login_fail');
function my_front_end_login_fail($username){
wp_redirect(site_url(). '?login=failed');
}
You can create a login failed action hook,
// hook failed login
add_action('wp_login_failed', 'my_front_end_login_fail');
function my_front_end_login_fail($username){
wp_redirect(site_url(). '?login=failed');
}