Need help with player movement

So, for the beginning, my english sucks, so i hope you guys can understand me.
My problem is that the jump animation just dont play, and i think its because i had no triggers, maybe you can explain me how to set the right triggers for my case.
I have this script for the movement.
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using UnityEngine;
using System.Collections;

public class ControlSalto : MonoBehaviour {

public string jump="Fire1";
public float jumpForce=1000.0f;
public Animator anim;
public bool grounded=false;
public Transform groundCheck;
public float retrasoSalto=0.5f;
private float tiempoSalto=0.0f;
// Use this for initialization
void Start () {
anim=gameObject.GetComponent<Animator>();
}


// Update is called once per frame
void Update ()
{
grounded=Physics2D.Linecast(transform.position , groundCheck.position);
tiempoSalto-=Time.deltaTime;
if(tiempoSalto<=0 && grounded){
anim.SetTrigger("isGrounded");
}

if(Input.GetKeyDown(KeyCode.Space))
{
anim.SetTrigger("isGrounded");
rigidbody2D.AddForce(transform.up*jumpForce);
tiempoSalto=retrasoSalto;
//cuerpoRigido2d.AddForce(transform.up*jumpForce);
}
}
}
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I think im missing the triggers, but i dont know how this works, instead of the triggers, i had this:


I need an doublejump script too because i can jump infinite times.