You have an error in your SQL syntax; check the manual that corresponds to your mariadb server version for the right syntax to use near '�a

Hello everyone!, I have a problem in my php code, the error is when I send my form data it throws me, this the error:

Error: INSERT INTO usuario(name,last,nameDad,nameMom,tipoIdentificacion,identificacion,telefono,email,address ,born,rango,estadoC,sex,contraseña) values ('Caca','acac','caca','acac','Venezolano:','123123123','123123123123','sdsds@gmail.com','jjashdjhasjd2!#F','128887-02-21','2131231','Viudo(A)', 'Man','sdsdsdsdsd')
You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near '�a) values ('Caca','acac','caca','acac','Venezolano:','123123123','1231231231' at line 2

<?php 
 
$dbhost = "localhost";
$dbuser = "root";
$dbpass = "";
$dbname = "clini";

$conn = mysqli_connect($dbhost,$dbuser,$dbpass,$dbname);
 
if(!$conn)
{
	die("No hay conexion:" .mysqli_connect_error());
}
 ?>
 
<?php 
 
 $nombre = $_POST['name'];
 $identi = $_POST['ci'];

//Login
if(isset($_POST["ingre"]))
{
	$query = mysqli_query($conn,"SELECT * FROM usuario WHERE nombre = '$nombre' AND identificacion='$identi'");
	$nr = mysqli_num_rows($query);
	
	if($nr==1)
	{
		echo "<script> alert('Bienvenido: $nombre,$appelidoC:'); window.location='home.php' </script>";
	}else
	{
		echo "<script> alert('Usuario no existe 😞'); window.location='index.php' </script>";
	}
}
  
  //Registrar
$name = $_POST["name"];
$apellido = $_POST["apec"];
$dad = $_POST["namep"];
$mom = $_POST["namem"];
$tipeCI = $_POST["tipeid"];
$ci = $_POST["ci"];
$phone = $_POST["te"];
$correo = $_POST["email"];
$add = $_POST["dirre"];
$day = $_POST["diana"];
$gradoI = $_POST["gradoin"];
$esC = $_POST["estado"];
$sex = $_POST["sex"];
$pass = $_POST["pass"];
  
if(isset($_POST["butt"]))
{
	$sqlgrabar = "INSERT INTO usuario(name,last,nameDad,nameMom,tipoIdentificacion,identificacion,telefono,email,address
	,born,rango,estadoC,sex,contraseña)
	values ('$name','$apellido','$dad','$mom','$tipeCI','$ci','$phone','$correo','$add','$day','$gradoI','$esC',
	'$sex','$pass')"; 
	
	if(mysqli_query($conn,$sqlgrabar))
	{
		echo "<script> alert('Feliciddes el usuario fue registrado con exito: $nombre'); window.location='index.html' </script>";
	}else 
	{
		echo "Error: ".$sqlgrabar."<br>".mysqli_error($conn);
	}
}
?>