Text for listView item won't display in WinForms C#, but the sub items text will

I have a ListView element in a form called Form1, which I have linked to another form called Form2, I have set up my code for a particlar event as follows:

 Form1.ToDoList.AddTask(Form1.ToDoList.task_list[task_ctr]);
        ListViewItem item_n = new ListViewItem(Form1.ToDoList.task_list[task_ctr].title);
        item_n.SubItems.Add(Convert.ToString(Form1.ToDoList.task_list[task_ctr].deadline));
        item_n.SubItems.Add(Convert.ToString(Form1.ToDoList.task_list[task_ctr].priority));
        if (Form1.ToDoList.task_list[task_ctr].complete == true)
            item_n.SubItems.Add("Yes");
        if(Form1.ToDoList.task_list[task_ctr].complete == false)
            item_n.SubItems.Add("No");


        form_1.listView1.Items.Add(item_n);

Text for listView item_n won't display in WinForms C#, but the text for the sub items will. When I change the line where item_n is initialised as follows:

ListViewItem item_n = new ListViewItem("example text");

It displays fine.

Any help would be appreciated.