Cant access a gameobject's position

Getting this error when trying to acces a gameobject attached to a gameobject in unity.

Error CS1061: ‘UnityEngine.GameObject’ does not contain a definition for ‘position’ and no extension method ‘position’ accepting a first argument of type ‘UnityEngine.GameObject’ could be found (are you missing a using directive or an assembly reference?) (CS1061) (Assembly-CSharp)

Here is the code used: (error is on groundCheck.position)
using UnityEngine;
using System.Collections;

public class NewBehaviourScript : MonoBehaviour {
	GameObject groundCheck;
	public bool grounded;
	public int jumpHeight = 5;
	void Start () {
	// Update is called once per frame
	void Update () {
		grounded = Physics2D.Linecast(transform.position, groundCheck.position, 1 << LayerMask.NameToLayer("Ground"));

		if (Input.GetKeyDown (KeyCode.Space) && grounded){
			rigidbody2D.velocity = new Vector2(rigidbody2D.velocity.x, jumpHeight); 


The error is precisely what it says it is. Objects of type GameObject (such as groundCheck) do not have a position field.

Perhapse you meant groudCheck.transform.position ?