player falls slowly

hi, I am very new to coding and i'm making a 3D top down game my player moves and jumps pretty nicely and smoothly but falls down slower than an astronaut in space backwards

using System.Collections; using System.Collections.Generic; using UnityEngine;

public class PlayerController : MonoBehaviour {

 public float movementSpeed = 30.0f;
 private float Vector3;
 public float jumpSpeed = 10f;
 public float gravity = 9.8f;



 void Start () {
     Cursor.visible = false;


 }
 
 // Update is called once per frame
 void Update ()
 {

      //walking 
         var x = Input.GetAxis ("Horizontal") * Time.deltaTime * movementSpeed;
         var z = Input.GetAxis ("Vertical") * Time.deltaTime * movementSpeed;

  
         transform.Translate (0, 0, z);
         transform.Translate (x, 0, 0);


         //jump
     var y = Input.GetAxis ("Vertical") * Time.deltaTime * movementSpeed;

     transform.Translate (0, y, 0);
     

         }

     



 }

i have tried dabbling around with the jump script but keep getting errors i also tried saying that if the space button is pressed the player jumps, then the code waits and after 2 seconds (when the player is it's highest) gravity is subtracted from the height